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toneohm 850a - Artisan Technology Group

1. Abb 4 Kurzschl sse an Leiterplatten Steckverbindern Hinweis Ware der KurzschluB bereits bei dem den AnschluBklemmen am n chsten liegenden Stecker so ware bereits zwischen Stecker 1 und 2 kein Ton mehr h rbar Kurzschl sse zwischen Busleitungen Die Testmethode TRACE eignet sich berall dort wo statische Kurzschl sse und keine Parallelkondensatoren vorhanden sind Fehler wie z B auf Versorgungsschienen f hren zu Fehlmessungen da die parallel zur Versorgung geschalteten Kondensatoren den Wechselstrom der Drive Source ableiten Busleitungen hingegen besitzen nur sehr geringe oder keine Kapazit ten deshalb ist die Stromfolger Methode oft der rascheste Weg zur Fehlereingrenzung Ist der Fehler bereits auf einen aus sechs Speicherbausteinen eingegrenzt so verwenden Sie die folgende Methode Schlie en Sie die Anschl sse der Drive Source an die defekten Leitungen an Stellen Sie die Empfindlichkeit so ein da die Sonde innerhalb 10mm einer Drive Source Anschlu leitung anspricht Halten Sie die Sonde auf jeden verd chtigen IC die dickste Seite der Sondenspitze parallel zur Seite der Anschl sse des ICs Der defekte IC leitet den eingespeisten Strom du
2. Fig 4 Court circuit sur connecteur e Ajuster le niveau de la source de fa on d tecter le courant a hauteur des connecteurs e D placer la sonde entre chaque connecteur en commen ant par le plus proche des fils de source e En d pla ant la sonde entre les connecteurs 1 et 2 2 et 3 3 et 4 il y a un signal sonore Et en d plagant la sonde entre les connecteurs 4 et 5 aucun son ne sort donc aucun courant ne parvient au connecteur 5 Cela indique que le court circuit est sur le connecteur 4 Note Si le court circuit avait t sur le connecteur le plus proche des fils de la source il n y aurait eu aucun signal sonore en d plagant les sondes entre les connecteurs 1 et 2 D fauts de bus noeuds bloqu s La m thode du traceur TRACE est utilisable lorsqu il n y a pas de capacit en parallele avec le d faut Les d fauts comme les surcharges d alimentation donnent des r sultats erron s cause des capacit s qui absorbent le courant alternatif de la source Les bus ont peu ou pas de capacit aussi lorsqu une ligne s croule ou est bloqu e la m thode TRACE est souvent la plus rapide La m thode de sectorisation d j d crite est efficace dans la plupart des cas Cependant lorsque le d faut est d a un circuit int gr situ en parall le avec cing ou six autres il y a un moyen plus rapide e Connecter la source aux bornes des lignes en d faut e Ajuster le niveau de la source de sorte que la sonde de
3. A rtisan Artisan Technology Group is your source for quality Fra op new and certified used pre owned equipment FAST SHIPPING AND SERVICE CENTER REPAIRS WE BUY USED EQUIPMENT DELIVERY Experienced engineers and technicians on staff Sell your excess underutilized and idle used equipment TENS OF THOUSANDS OF at our full service in house repair center We also offer credit for buy backs and trade ins IN STOCK ITEMS www artisantg com WeBuyEquipment 7 EQUIPMENT DEMOS HUNDREDS OF Instra 4 REMOTE INSPECTION LOOKING FOR MORE INFORMATION MANUFACTURERS Remotely inspect equipment before purchasing with Visit us on the web at www artisantg com 7 for more our interactive website at www instraview com information on price quotations drivers technical LEASING MONTHLY specifications manuals and documentation RENTALS ITAR CERTIFIED alte Contact us 888 88 SOURCE sales artisantg com www artisantg com Polar Instruments Ltd Aide Cai TONEOHM 850A Slory OPERATOR an MAN UAL http www polar co uk Fax 44 0 1481 252476 Email mail polar co uk MAN 150 9803 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com rtisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A SHORTS LOCATOR OPERATOR MANUAL POLAR INSTRUMENTS LTD HARDWARE WARRANTY 1 Product Warranty Product hardware is warranted to b
4. MILLIOHMMETER TRACK VOLTAGE CURRENT TRACING SIMPLE MAINTENANCE INTRODUCTION An overview of the Polar TONEOHM 850A shorts locator and its applications The principles of operation of the TONEOHM 850A selecting the operating mode for different types of short circuit Front and rear panel connectors Connecting the TONEOHM 850A to a power supply Using the resistance measurement ranges of the TONEOHM 850A to locate low resistance short circuits Making track voltage measurements with the TONEOHM 850A to locate high resistance shorts and loading faults Non contact current tracing with the TONEOHM 850A Using board sectoring techniques to pin point faults on printed circuit boards Locating shorts in wire looms and backplanes Details of maintenance and cleaning procedures Vii Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL CONTENTS BEGEARATIONS eege Eege ii European Community Directive Conformance Statement ii SOARED E iii WARNING eege ee a Rn ee EES iii GROUNDING airina tn nie oie nibs ell aie ae iii POWER SUPPLY EE iv TONEOHM 850A OPERATION uses iv SPEGIFICATIONS 2 v ENVIRONMENTAL OPERATING CONDITIONS sisi v ee vi ele Ee WEE vi SY EL ET vi SECTION 1 INTRODUCTION EENS SEENEN EES 1 1 INTRODUCTION TO THE TONEOHM 850A ii 1 1 1 1 Using the TONEOHM 850A to locate short circuits 1 1 TONEOHM 8
5. Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDA PER L UTILIZZATORE Selezione del modo e della portata Quando occorre selezionare la portata e necessario considerare le seguenti domande e Ildifetto e un corto circuito a bassa resistenza per esempio inferiore a 200MQ e Il difetto e statico sempre presente Utilizzare la tecnica Milliommetro e Il difetto e dinamico presente solo quando la scheda e alimentata Utilizzare il modo TRACK VOLTAGE e Se l accesso e difficoltoso utilizzare il puntale CURRENT TRACE ad esempio per ricercare la corrente senza eseguire delle contattazioni e l corto circuito riguarda un piano di un circuito stampato multistrato In questo caso l Utilizzatore deve utilizzare il modo TRACK VOLTAGE La tabella che segue indica le portate da selezionare per i differenti tipi di corto circuiti da ricercare Soros ana na N I Corto su scheda ac rae TRACE dinamico Difetto su un Bus TRACE Backplane cavi di connessione TRACE LB Condensatori a circuito aperto TRACE Tabella 1 portate del localizzatore di corti 850A Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com MILLIOMMETRO LOCALIZZAZIONE DI CORTO CIRCUITI PONTI DI STAGNO E DEPOSITI CONDUTTIVI MILLIOMMETRO LOCALIZZAZIONE DI CORTO CIRCUITI PONTI DI STAGNO E DEPOSITI CONDUTTIVI NOTA Scollegare l alimentazione dalla sched
6. or differences between readings of less than 15uV Readings as small as these can be caused by thermoelectric voltages instead of PCB track currents For this reason the 850A does not produce a tone for readings below about 5011V 5 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com rtisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 6 CURRENT TRACING NOTE Disconnect power from the board under test before using TRACE NON CONTACT CURRENT TRACING The non contact current tracing method of locating shorts will be found especially useful where tracks and components are difficult to access Densely populated double sided PCBs Environmentally coated PCBs Cable looms Multi layer boards where the short is on an inner layer The operator will normally use TRACE mode to detect the current flowing in tracks which cannot be probed using the Needle Probes e g a track running under an IC or in the middle layer of a multi layer PCB When using TRACE the current must be supplied by the Drive Source leads 6 1 Using the 850A Drive Source The TONEOHM 850A s Drive Source drives current through the circuit under test and the resulting magnetic field may be detected using the Current Trace Probe The maximum voltage generated by the Drive Source is 550mV which will not damage devices or turn on silicon junctions
7. 20mm l un de l autre pr s des coins de la carte secteur 3 sur le dessin e 3 D placer la sonde de courant le long des lignes AB et puis CD pour savoir si le courant passe du secteur 3 aux autres secteurs Si le courant est d tect le long de ces lignes alors le courant circule dans un autre secteur Si c est le cas changer la position des fils de source dans un secteur diff rent et r p ter l op ration e 4 Continuer de d placer la source du 850A jusqu ce qu aucun courant ne sorte du secteur ou l alimentation est branch e La position du court circuit est dans ce secteur e 5 R p ter l op ration dans ce secteur jusqu ce que le d faut soit isol dans un carr de 20mm de cote Connecteurs sur fond de panier La localisation d un court circuit entre 2 broches d un connecteur se fait en branchant les fils SOURCE comme indiqu sur la figure 4 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TRACEUR DE COURANT SANS CONTACT 1 2 3 4 5 COURT CIRCUIT DRIVE SOURCE
8. 850A to a power supply Refer to the voltage label on the rear panel of the instrument and make sure that the marked rating is suitable for the local mains power supply If the rating on the label is not suitable for the local power supply refer the instrument to a skilled electronics technician Instructions for changing the line voltage settings are contained in the TONEOHM 850A Service Manual Note If a special local plug must be fitted to the power cord ensure this operation is performed by a skilled electronics technician and that the protective ground connection is maintained The plug that is cut off from the power cord must be safely disposed of Power cord color codes are as follows Europe brown live blue neutral green yellow earth ground United States black live white neutral green ground Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL Check that the TONEOHM 850A mains switch on the rear panel is OFF Plug the power cable into the receptacle on the rear panel of the TONEOHM 850A Plug the other end into a wall outlet 3 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 4 MILLIOHMMETER LOCATING SOLDER AND LAND BRIDGES NOTE Disconnect power from the board under test before using any of the resistance ranges 4 1 Low resistance shorts Low resistan
9. TRACK VOLTAGE shorts locating mode nn 5 1 Statio faults O 5 1 EXCESSIVE Vec Loads EE 5 1 Dynamic CIE 5 2 SECTION 6 CURRENT TRACING uuuussuunnaannnnannnnnnnnnnnannnnnnnnnannnnnnnnnnnnnnnnnnnnnannnnnnnnnnnnnnnannnnnnannnnnnnnnnn 6 1 NON CONTACT CURRENT TRACING sense caeeeeaaeeseeeeecaesesaeeseaeeenaes 6 1 6 1 Using the 850A Drive Source iii 6 1 Connection and Sensitivity Adjustment ss 6 2 SER E le EE 6 2 Board SeCtOrINg EE 6 2 Bus Faults St ck Nodes EE 6 3 Edge Connector Serenan een eo 6 5 Faulty Decoupling Capacitors ann 6 6 SECTION 7 SIMPLE MAINTENANCE AND CLEANING is isnmmnnrnnnenneennennnnmnnennte 7 7 CNS UNI DEE 7 7 Technical Support a iaia DO PO eee es eee 7 7 USER GUIDE FRENCH USER GUIDE GERMAN USER GUIDE ITALIAN Ix Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com rtisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 1 INTRODUCTION INTRODUCTION TO THE TONEOHM 850A Short circuits and loading problems are a common cause of faults in electronic instrumentation both at the manufacturing stage and in service and repair These faults may range from a low resistance short such as a solder bridge on a printed circuit board to a defective component loading down a bus line ina complex microprocessor system 1 1 Using the TONEOHM 850A to locate short circuits With the TONEOHM 850A the op
10. Voltage mode 3 Are the tracks or cables associated with the short accessible If access is difficult e g a wire harness or densely packed memory bank it will probably be most appropriate to use the Current Trace Probe i e to detect current without making contact 4 Does the short involve a plane in a multi layer board In this case the operator should use Track Voltage mode 2 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL The table below indicates the suggested range for locating different types of short circuit EE ame NO NO Table 2 1 850A Short Location ranges 2 4 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 3 INSTALLATION AND SET UP PREPARATION FOR USE 3 1 Unpacking The instrument is shipped in a sturdy transit pack Open the pack carefully and remove the instrument and its accessories If the instrument is damaged in any way contact the local distributor or supplier Retain the pack for possible future use The TONEOHM 850A pack should contain TONEOHM 850A Power cord Pair of needle probes Current Trace Probe Drive Source leads Operator manual Note If the instrument has been shipped or stored in a cold environment allow the instrument to reach the temperature of its new location before applying power 3 2 Connecting the TONEOHM
11. courant par la mesure de la tension de piste Utiliser ces gammes sur des pistes peu r sistives Traceur de courant Mesure de courant sans contact pour les cas d inaccessibilit aux pistes ou aux composants Le TONEOHM 850A poss de un afficheur LCD et un signal sonore a tonalit variable pour indiquer la proximit du court circuit Cette aide sonore permet a l op rateur de progresser dans la recherche sans quitter les pistes des yeux Utilisation d un casque Le bouton VOLUME contr le le niveau sonore du signal le branchement du casque d connecte automatiquement le haut parleur interne Utiliser uniquement des prises jack st r o 3 5mm Utilisation des sondes du TONEOHM 850A L appareil est fourni avec des sondes a pointes de touche une sonde de traceur de courant et un jeu de fils source Chaque sonde a son propre connecteur de branchement Lorsque les gammes de TRACK VOLTAGE sont s lectionn s la sortie Drive source d livre une tension continue utilisable pour stimuler la carte sous test Les polarit s sont donn es par les couleurs des fils soit positif sur la rouge et n gatif sur le noir Si l appareil est en mode Traceur s lection de TRACE la source est alternative Connexion du TONEOHM 850A au secteur S assurer que la tension d alimentation indiqu e a l arri re de l appareil est conforme celle fournie V rifier que l interrupteur marche arr t du TONEOHM 850A est sur arr t OFF Relier le cordon d
12. is first divided into four sectors see Fig 6 1 6 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com CURRENT TRACING Fig 6 1 Board Sectoring 2 Connect the Drive Source Leads 10 20mm apart near one corner of the board Sector 3 in the illustration 3 Move the Trace Probe along the lines AB then along CD to determine if current is flowing out of Sector 3 into the other sectors If current is detected along these lines then it is flowing into another sector If so alter the position of the Drive Source leads to a different sector and repeat 4 Continue to move the Drive Source until no current is flowing out of the sector where the Drive Source is connected The position of the short is now somewhere within that sector 5 Repeat the above process within that sector until the fault is isolated to within a 20mm square Use of the circuit diagram combined with knowledge of the current path will often quickly identify a likely place for a short eg two adjacent IC pins Bus Faults Stuck Nodes Where a Static fault exists between two points that have no parallel capacitors TRACE can be used to locate the fault TRACE is usually unsuitable for locating Vcc loading faults as power supplies are likely to have high value electrolytic capacitors connected These will produce misleading results because the capacitors will conduct AC current from the Drive Source Bus lin
13. le terminazioni DRIVE SOURCE distanziate di 10 20 mm in prossimita di un angolo della scheda e Muovere il puntale TRACE lungo la linea AB quindi lungo la linea CD in modo da determinare se la corrente scorre al di fuori del settore 3 in un altro settore Se e cosi modificare la posizione delle terminazione DRIVE SOURCE posizionandole in un altro settore Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com LOCALIZZAZIONE DELLA CORRENTE CURRENT TRACE SENZA CONTATTAZIONE S DRIVE 4 f Figura 3 Divisione della scheda in settori I I I I I I T I I I I I I I I I I I I I A l B I I I I I I I I I I I I I I I I I I I e Muoverele terminazioni DRIVE SOURCE sino a che non si individua il settore al di fuori del quale la corrente non circola Il corto circuito e posizionato all interno della sezione individuata e Ripetere il processo appena descritto all interno del settore individuato sino a che si isola una superficie quadrata di 20 mm Connettore piatto Corto circuiti tra due pin di una riga di connettori piatti possono essere rilavati collegando le terminazioni DRIVE SOURCE come indicato in figura 4 e Regolare il controllo del DRIVE SOURCE in modo da ottenere una lettura con il puntale all altezza del connettore piatto e Muovere il puntale sotto l interstizio di ogni connettore iniziando da quello piu vicino alle terminazio
14. voltage drop caused by the current flowing in a track This technique will be found effective when tracing loading faults and high resistance shorts Current Tracer The 850A Current Tracer is most effective where access to tracks or components is difficult i e when non contact current tracing is required 2 2 Controls connectors and probes Controls RESISTANCE range switches The RESISTANCE ranges Q 200mQ and 20 are used to locate low resistance shorts When locating faults on heavier tracks use the range to gain more sensitivity and resolution Use the 2000 20KQ ranges for general resistance measurements Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL When using the millionmmeter ranges the open circuit probe tip voltage is limited to a maximum of 60mV to prevent any damage to sensitive components TRACK VOLTAGE range switches The TRACK VOLTAGE ranges 2mV 20V allow the operator to trace current through a printed circuit board track from the voltage drop along sections of the track The displayed value corresponds to the voltage along the track The 20mV and 2mV ranges are particularly useful where the tracks are wide i e very low resistance DRIVE SOURCE control The TONEOHM 850A s Drive Source drives current through the circuit under test the resulting magnetic field may be detected using the Current Trace Probe T
15. 50A applications iii 1 1 TONEOHM 850A display mechantems nn 1 1 SECTION 2 DESCRIPTION iii iii inizia 2 1 LOCATING SHORT CIRCUITS WITH THE TONEOHM 850A anna 2 1 2 1 TONEOHM 850A shorts locating Modes i 2 1 lte anainn WEE 2 1 Track e EE 2 1 Current TIACEri ii dune cds ei aio 2 1 2 2 Controls connectors and probes sise 2 1 CONOIS EE 2 1 RESISTANCE range switches iii 2 1 TRACK VOLTAGE range switches iii 2 2 DRIVE SOURGE control pia Rn einladen 2 2 VOLUME CONTON een 2 2 Audio TONO te LEE 2 2 GONNECIONS ci iii lia di ilaria 2 2 Headphone SOCKEt cc 2 2 Current trace probe and drive source leads 2 2 Neede tel 2 3 2 3 Rear Panel controls and connectors nanen ri anuna eann Nn NNE Naaa 2 3 2 4 Mode and range selection seen 2 3 SECTION 3 INSTALLATION AND SET UP neri 3 1 PREPARATION FOR USE wis esc aie sified na leit hed NEESS Ee 3 1 gT Unpack le EE 3 1 3 2 Connecting the TONEOHM 850A to a power supply nn 3 1 vili Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com INTRODUCTION SECTION 4 MILLIOHMMETER i ein 4 1 LOCATING SOLDER AND LAND BRIDGES nn 4 1 4 1 LOW r sistance Shots acer dee een in nent vaccines 4 1 Tracing faults on double Sided boards 4 1 SECTION 5 TRACK VOLTAGE fn EENS 5 1 USING TRACK VOLTAGE TO LOCATE LOADING FAULTS namens nenn 5 1 5 1
16. ACK VOLTAGE Ce mode permet a l op rateur de suivre le courant d une piste grace aux chutes de tension le long de cette piste La valeur affich e et la tonalit correspondent a la tension le long de la piste Comme le son est proportionnel la tension mesur e il est souvent suffisant de suivre les changements de tonalit plut t que de v rifier les valeurs affich es Si la mesure de tension devient n gative un signal strident se produit pour signaler l inversion de la polarite Le d faut peut tre statique toujours pr sent ou dynamique pr sent quand la carte est sous tension D fauts statiques D connecter l alimentation de la carte en test Utiliser la source de courant de l appareil pour alimenter les pistes de la carte sur lesquelles on v rifie la tension Utiliser les gammes 20mV et 2mV en particulier quand les pistes sont larges c est dire faible r sistance Charges excessives d alimentation Les d fauts typiques sont l croulement des rails d alimentation VCC cr par des composants d fectueux faible r sistance qui tirent un courant excessif Consid rons l exemple de la carte de la Fig 2 o le VCC est en surchage Nous supposons que le d faut est statique et que les pistes sont larges Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDE UTILISATEUR DRIVE SOURCE Cl C2 C3 C4 C5 MASSE Fig 2 Mesure de
17. CE cosi da essere utilizzato congiuntamente all uscita dei DRIVE SOURCE Il controllo dei DRIVE SOURCE e utilizzato per regolare l ampiezza della corrente Il DRIVE SOURCE LED indica la circolazione della corrente DRIVE SOURCE La sensibilita del puntale CURRENT TRACE dipende dall orientamento della punta La minima sensibilita si ottiene quando la linea nera del puntale non e orientato in direzione di una pista che porta la corrente Girando il puntale di 90 sopra la pista che porta la corrente in modo che la linea nera si trovi posizionata direttamente sulla pista del circuito stampato si ottiene la massima sensibilita Questo viene rilevato attraverso un incremento della misura visualizzata sul Display e dal corrispondente aumento della frequenza del tono Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDA PER L UTILIZZATORE Regolazione della sensibilita e collegamento dei puntali Il modo migliore per utilizzare il Modo TRACE e collegare le terminazioni separate da 10 20 mm sulla scheda sotto test non collegare le terminazioni agli angoli opposti della scheda Collegare le terminazioni dei DRIVE SOURCE sopra la pista in corto circuito e regolare il controllo del DRIVE SOURCE completamente in senso orario Posizionare il puntale CURRENT TRACE vicino a una delle terminazioni DRIVE SOURCE Avvicinando il puntale alle terminazioni la misura visualizzata sul di
18. Its amplitude can be adjusted using the Drive Source control The sensitivity of the Current Trace Probe depends on the orientation of its tip Minimum sensitivity occurs when the black lines on the probe tip are either side of the PCB track carrying the current Turning the probe through 90 over a current carrying track so that the black lines are directly over the PCB track produces maximum sensitivity This will result in an increasing display reading and rising tone frequency Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL Connection and Sensitivity Adjustment Connect the Drive Source leads across the shorted tracks and turn the Drive Source control fully clockwise The most effective way to use TRACE is to connect leads 10 20mm apart on the board under test Unless there is a good reason do not site the leads at opposite corners of the board The DRIVE SOURCE LED indicates flow of Drive Source current If the LED does not light either the leads are connected incorrectly or there may be insufficient current flowing for the Current Trace Probe to detect the resulting field Hold the Current Trace Probe near one of the Drive Source leads As the probe approaches the lead the LCD reading and the tone frequency should increase as the probe senses the flow of current Position the probe for maximum reading against one of the Drive Source lea
19. Polar Instruments Ltd 1995 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL DECLARATIONS European Community Directive Conformance Statement This product conforms to all applicable EC Council Directives including EC Council Directive 89 336 EEC on the approximation of the laws of the Member States relating to electromagnetic compatibility EC Council Directive 73 23 EEC on the harmonisation of the laws of the Member States relating to electrical equipment designed for use within certain voltage limits A declaration of conformity with the requirements of these Directives has been signed by POLAR INSTRUMENTS UK LTD 11 College Place London Road Southampton England SO1 2FE Harmonised standards applied in order to verify compliance with these Directives EN 50081 1 1992 EN 50082 1 1992 EN 61010 1 1993 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com INTRODUCTION SAFETY WARNING The LIVE and NEUTRAL lines on this unit are BOTH fused This unit contains no user serviceable parts When the unit is connected to its supply the opening of covers or removal of panels is likely to expose dangerous voltages To maintain operator safety do not operate the unit unless the enclosure is complete and securely assembled GROUNDING This unit must be earthed grounded do not operate
20. TURERS Remotely inspect equipment before purchasing with Visit us on the web at www artisantg com 7 for more our interactive website at www instraview com information on price quotations drivers technical LEASING MONTHLY specifications manuals and documentation RENTALS ITAR CERTIFIED alte Contact us 888 88 SOURCE sales artisantg com www artisantg com
21. V ranges should be used for tracing the flow of a DC current through a PCB track This is particularly applicable where the tracks are wide i e very low resistance Disconnect power from the board under test if the Drive Source is used Excessive Vcc Loads A common power supply loading problem shows up as a power supply rail Vcc being held low by a faulty device drawing excessive current This is not a low resistance short less than 200m or the rail would read OV with respect to ground and the resistance measurement shorts location procedure Section 4 could be used The fault may be caused by a component going low resistance producing a permanent low resistance between Vcc and ground This is an example of a static fault which remains when power is removed from the board under test Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL Example Consider the board shown in Fig 5 1 where the Vcc supply is being loaded Assume the fault is static and the tracks are wide i e very low resistance co SA CR DRIVE SOURCE Cl C2 CG C4 C5 GND Fig 5 1 Track Voltage Measurement 1 Connect the Drive Source leads across the Vcc and ground connections of the board Select the 2mV range and set the DRIVE SOURCE control to maximum The path of the Drive Source current can now be followed to locate the faulty device on 4 Using the Needle Prob
22. a sotto test prima di utilizzare una qualsiasi portata per la misura di resistenza Corto circuiti di bassa resistenza Utilizzare la portata 200mohm per cortocircuiti a bassa resistenza con resistenze inferiori a 200mohm ad esempio ponti stagno e depositi conduttivi tra piste adiacenti o punti di saldatura Per piste piu consistenti utilizzare la portata ohm Tenere un puntale all angolo destro della scheda e applicare una pressione sufficiente per perforare il flussante o il solder resist in modo da posizionare il puntale in punti differenti della pista Se il corto circuito non e visibile utilizzare un bisturi per incidere il solder resist presente tra le piste Nel circuito di esempio indicato in figura 1 esiste un corto circuito tra l uscita di U1 e l ingresso di U2 L alimentazione della scheda e scollegata e i puntali a perforazione sono posizionati nei punti A ed E La resistenza tra le piste per la presenza del corto circuito offre una misura e la generazione di un tono Muovendo il puntale da A a B otteniamo una misura inferiore e un tono maggiore Questo significa che ci stiamo muovendo nella direzione del corto circuito Muovendo il puntale da B a C otteniamo una lettura superiore e un tono inferiore Questo indica che il puntale si sta allontanando dal difetto Questo implica che il difetto e tra B e C Ora muovere il puntale da E in modo da ottenere un misura inferiore e una maggiore frequenza Quando la lettura e infer
23. alimentation secteur l appareil S lection du mode et de la gamme Pour choisir la gamme appropri e consid rer les points suivants e S agit il d un court circuit franc par exemple moins de 200m9 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDE UTILISATEUR e Est ce que le d faut est statique Utiliser le millionm tre Est ce que le d faut est dynamique apparait il seulement quand la carte est aliment e Utiliser le mode tension de piste e Sil acc s est difficile il sera pr f rable de prendre la fonction traceur de courant e Est ce que le court circuit implique un plan dans une carte multicouche Dans ce cas utiliser le mode tension de piste Le tableau ci dessous sugg re les gammes et les modes a utiliser en fonction du type de court circuit Type de d faut Gamme Drive Source Cartesitension dynamique Defaut de Bus TRACE Capacit de d couplage coup e TRACE Fond de panier cables TRACE Table 1 850A Choix des gammes selon le d faut MILLIOHMETRE LOCALISATION DES PONTS DE SOUDURE NOTE D connecter l alimentation de la carte sous test avant d effectuer des mesures de r sistances Courts circuits francs faible r sistance Utiliser la gamme 200mQ pour les courts circuits de faible r sistance inf rieure 200mQ comme les points de soudure entre pistes ou points adjacents Tenir la pointe vert
24. artisantg com KONTAKTLOSE STROMVERFOLGUNG GND Abb 2 Spannungsfolger Messung Track Voltage Hinweis W ren die Drive Source Anschlu kabel ber C3 angeschlossen worden so h tten alle Spannungsmessungen Null ergeben Tritt diese Situation ein so ist ein AnschluBkabel anders anzuschlieBen z B an C2 welches einen Spannungsabfall an den Leiterbahnen zu C3 zur Folge hatte Dynamische Fehler Dynamische Fehler werden mit angelegter Versorgungsspannung Lokalisiert In diesem Fall ist der gemessene Stromflu eine Kombination aus normaler Belastung und der berlast durch den defekten Bauteil Es wird nun bei angelegter Versorgungsspannung der Stromflu durch die Leiterbahnen und deren Verzweigungen mittels Spannungsabfallsmessung verfolgt HINWEIS Kleine MeBwerte um 15uV sind oft die Ursache von thermoelektrischen Effekten und nicht Ursache von Stromfl ssen Aus diesem Grund erzeugt der TONEOHM 850A keinen Ton f r Me werte kleiner 50uV KONTAKTLOSE STROMVERFOLGUNG HINWEIS Entfernen Sie die Versorgung der Leiterplatte vor der Anwendung von TRACE Verwenden der TONEOHM 850A Drive Source Die Drive Source des TONEOHM 850A speist die zu testende Schaltung ber die Drive Source Anschlu kabel rot und schwarz das resultierende Magnetfeld kann mit der Stromfolgersonde detektiert werden kann Die Sonde ist auf die Frequenz des Wechselstroms eingestellt den die Drive Source liefert Die Sonde kann also nur zusammen mit de
25. ce shorts are shorts having a resistance under 200 mQ caused typically by a solder or land bridge These shorts often occur between adjacent tracks or solder joints on a PCB Using the 200 mQ range the operator should easily isolate the fault to within a few millimetres In situations involving heavier tracks more sensitivity and resolution can be gained using the range As the 850A uses DC for the millionmmeter ranges capacitors do not affect its accuracy The open circuit probe tip voltage is limited to a maximum of 60mV to prevent any damage to sensitive components To obtain the best results and minimise damage to the track hold the probes at right angles to the PCB and apply sufficient pressure to pierce flux and solder resist Probe the track at different points rather than scraping the probe along its length It is not unusual for a fault to be located between two parallel tracks where there is no visual sign of a short even if the board is examined with an eyeglass This often happens if the board is covered with solder resist masking a hairline whisker short Use a scalpel to cut between the tracks through the solder resist and the short An open circuit reading in a subsequent measurement confirms that the fault has been cleared Tracing faults on double sided boards Generally the same technique should be applied to both single and double sided boards where physically possible On a densely populated board where very li
26. courant r ponde environ 10mm de l un des fils e D placer la sonde au dessus de chaque circuit suspect avec le grand cot parall le la ligne e Le CI d fectueux aura un courant de substrat suffisant pour tre d tect par la sonde Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com rtisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A KURZANLEITUNG EINFUHRUNG Der TONEOHM 850A kann jede Art von Kurzschlu mittels drei unterschiedlichen Betriebsarten lokalisieren Millionmmeter W hlen Sie den Bereich Q oder 200mQ wenn Sie niederohmige Kurzschl sse auffinden wollen Die h herohmigen MeBbereiche 22 2009 und 20KQ wurden f r bliche Widerstandsmessungen implementiert Track Voltage Dieser Bereich eignet sich besonders f r Fehllasten und hochohmige Kurzschl sse W hlen Sie die Bereiche 2mV und 20mV um Stromfl sse durch Spannungsabfallsmessung entlang einer Leiterbahn zu verfolgen Verwenden Sie diese Bereiche f r Messungen an breiten Leiterbahnen Current Trace Kontaktlose Stromverfolgung bei schwer zug nglichen Leiterbahnen Der TONEOHM 850A Kurzschlu lokalisator besitzt ein LCD Display und zus tzlich einen frequenzvariablen Tongenerator um die Entfernung zum Kurzschlu anzuzeigen Der vom Tongenerator abgegebene Ton erm glicht es dem Anwender st ndig visuellen Kontakt mit der zu testen
27. den Schaltung zu halten Anwendung des Kopfh reranschlusses Mit der Lautst rkeeinstellung VOLUME kann die Lautst rke des Testtones ver ndert werden Wird an die Buchse ein Kopfh rer angeschlossen so wird der eingebaute Lautsprecher abgeschaltet und der Ton auf die Kopfh rer geleitet Verwenden Sie ausschlie lich Kopfh rer mit 3 5mm Stereoklinkenstecker Anwendung der TONEOHM 850A Pr fspitzen Probes Im Lieferumfang des TONEOHM 850A sind Nadelspitzen eine Stromfolgersonde und ein Satz Anschlu klemmen f r die Treiberquelle Drive Source enthalten Jede dieser Probes pa t nur in die geeignete Anschlu buchse auf der Frontplatte Sind die Bereiche TRACK VOLTAGE gew hlt so liefert die Treiberquelle eine Gleichspannung rote Klemme positiv die zur Anregung des Testobjekts verwendet werden kann Die rote positive und die schwarze negative Markierung auf den Pr fspitzen kennzeichnet die Stromflu richtung im Modus TRACK VOLTAGE Ist die Betriebsart TRACE ausgew hlt so ist das Ausgangssignal eine Wechselspannung Mit Ausnahme der Betriebsart TRACE sind die Nadelpr fspitzen zu verwenden Anschlu des TONEOHM 850A an die Netzversorgung Vergewissern Sie sich ob die auf der Ger ter ckseite aufgedruckte Netzspannung mit der lokalen Netzversorgung bereinstimmt berpr fen Sie ob der Netzschalter des TONEOHM 850A auf der Ger ter ckseite in der Stellung OFF steht Schlie en Sie nun das Netzkabel in die zugeh
28. ds Adjust the DRIVE SOURCE control to give a reading of 100 to 130 If the reading is less than 100 leave the control at maximum this occurs with high resistance shorts i e above 150Q To alter the distance over which the probe detects current adjust the DRIVE SOURCE control 6 2 Operation Unlike the milliohm ranges when using TRACE the probe does not gradually approach the fault giving a highest tone when it is reached Instead the probe indicates the path of the current Since the reading and tone are proportional to the detected field it is evident when the probe is moving away from the current carrying track When using the Trace Probe to follow circuit current take care not to detect the magnetic field from the Drive Source leads draped over the PCB When using TRACE the operator s primary objective is to find a position where the Drive Source leads can be clipped onto the board under test such that the Trace Probe detects no field outside a 15 to 20mm square adjacent to the leads This will mean that the fault must be within that square The most effective method is board sectoring Board Sectoring Attempting to locate the fault without moving the Drive Source leads will usually prove unsuccessful without some familiarity with the PCB layout The most succesful approach will probably be to move the injection points of the Drive Source around the board to determine in which regions there is current flowing 1 The board
29. e free from defects in material and workmanship during the Warranty Period as defined below Product hardware is warranted to conform substantially to Polar s then current as of the date of Polar s product shipment published user documentation during the Warranty Period The Warranty Period is twelve 12 months Product support beyond these periods may be available at additional cost consult Polar for details 2 Warranty Claims Polar shall incur no liability under this warranty if the end user fails to provide Polar with notice of the alleged defect during the applicable Warranty Period and within seven 7 days of delivery to end user or if the defect would not have been reasonably apparent on inspection within seven 7 days of its discovery by end user After receiving such notice Polar will notify the purchaser of its designation of one of the following problem resolution methods Return to Factory The allegedly defective goods must be returned to Polar within seven days of Polar s notice and in accordance with Polar s instructions advised at the time Other Polar will use commercially reasonable efforts to repair correct or work around the problem by means of telephone support or other means reasonably determined by Polar Polar shall incur no liability under this warranty if Polar s tests disclose that the alleged defect is due to causes not within Polar s reasonable control including alteration or abuse of the good
30. er vom Kurzschlu punkt entfernt der Ton beginnt zu intermittieren KURZSCHLU Abb 1 Niederohmiger Kurzschlu Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A KURZANLEITUNG LOKALISIEREN VON FEHLLASTEN MITTELS TRACK VOLTAGE HINWEIS DER SPANNUNGSUNTERSCHIED ZWISCHEN BEIDEN PRUFSPITZE GEGENUBER MASSE DARF 50V NICHT UBERSCHREITEN Die Kurzschlu lokalisierung mittels Spannungsfolger erm glicht die Verfolgung von Str men auf einer Platine durch den entstehenden Spannungsabfall an den Leiterbahnen Der Anzeigewert und der abgegebene Ton entspricht der H he des gemessenen Spannungsabfalls an einer Leiterbahn Da sich auch die Tonh he mit dem gemessenen Spannungsabfall proportional ndert ist es normalerweise einfacher sich an der Tonh he zu orientieren anstatt die Anderungen am Display zu beobachten Ist die gemessene Spannung negativ so warnt ein intermittierender Ton vor der falschen Polarit t der Pr fspitzen Werden Str me durch Leiterbahnen verglichen so mu der Abstand der Pr fspitzen zueinander gleich sein Fehler k nnen sowohl statisch d h immer vorhanden als auch dynamisch d h nur vorhanden wenn Leiterplatte versorgt auftreten Statische Fehler Schlie en Sie im Falle eines statischen Fehlers die Versorgung der Baugruppe ab und verwenden Sie f r die Versorgung die Treiberquelle Drive Source um die Spannungsabf lle entlang einer Le
31. erator has the choice of three operating modes to locate any type of short circuit without damaging the board under test Millionmmeter For locating low resistance shorts Track Voltage Measuring the voltage drop caused by current flow through a track Useful when tracing loading faults and high resistance shorts Current Trace Non contact current tracing where access to tracks or components is difficult TONEOHM 850A applications The high accuracy of the TONEOHM 850A allows it to be used for a wide variety of applications requiring low resistance measurements e Continuity testing e Relay and switch contact measurements e Detecting and measuring high resistance connections e Measurement of transformer winding resistance e Testing for shorts and partial shorts between transformer windings TONEOHM 850A display mechanisms The TONEOHM 850A incorporates two mechanisms for notifying the operator of the proximity of a short circuit a liquid crystal display digital readout and a highly sensitive variable frequency audio tone output The inclusion of the audio tone system allows the operator to maintain visual contact with the circuit under test while tracing through dense or complex wiring The TONEOHM 850A will rapidly pin point the physical location of short circuits in many cases to within 0 2 inches both on PC boards in isolation and within circuit wiring without the need to disconnect associated components or wiring Artisan Technolo
32. erator to trace current through a printed circuit board track from the voltage drop along sections of the track The displayed value and tone correspond to the voltage along the track This voltage is proportional to the current flowing through the track but will also vary with the distance between the probes and the resistance of the track e g a current flowing through a narrow track will develop a larger voltage drop than the same current flowing through a wide track When comparing the current flow through tracks the distance between the probes should be kept approximately constant As the tone is proportional to the voltage across the probes it is usually sufficient to follow the tone change rather than to check readings If the measured voltage is negative a warble is generated as a warning of reversed polarity Faults may be categorised as static i e the fault is always present whether or not the circuit is powered up or dynamic the fault is only present when power is applied to the circuit Static faults If the fault is static it is recommended that the Drive Source be used to supply the current while checking voltage drops along circuit board tracks the Drive Source is connected between the faulty nodes Its output of 550mV will not damage devices or turn on silicon junctions this will make tracing of the current flow easier As the Drive Source output is DC decoupling capacitors do not affect operation The 20mV and 2m
33. es measure the voltage between A and B The reading is 1 257mV indicating high current flow 5 Measure the voltage between B and C The reading is 1 118mV suggesting approximately the same current flow 6 Measure the voltage between C and D The reading is 0 018mV current is low suggesting that the current in BC must be flowing through C3 i e C3 has gone low resistance Note that if the Drive Source leads had been connected across C3 all voltage measurements would be zero If this happens the solution would be to move one of the leads e g to C2 giving a PCB track drop leading to C3 Dynamic faults Another common component failure is an IC that draws excessive current causing the Vcc rail to be held low when the board is powered When the board is unpowered the Vcc to ground resistance is normal This is an example of a dynamic fault 5 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com VOLTAGE MEASUREMENT For a dynamic fault it will be necessary to test the board in its powered up state In this case the current flow that is traced will be a combination of the normal load to devices connected to the supply and the excess current due to the fault With power applied the operator traces the current flow through the track and its branches by measuring the voltage drop along the track due to the current flowing in it NOTE Do not rely too much on voltage readings
34. es have little or no capacitance so when one device is known to be holding the bus down current tracing is often the quickest way to isolate the fault The sectoring technique described previously is effective in most cases However it may be that the fault is already known to be in one of five or six memory ICs in which case there is a quicker method 6 3 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL 1 Connect the Drive Source leads across the faulty lines 2 Adjust the Drive Source control so that the Trace Probe responds within 10mm of one of the Drive Source leads 3 Pass the Probe over each suspect IC with the thickest sides of the probe tip parallel to the IC pin sides 4 The defective IC will be conducting Drive Source current through its substrate this current will be detected by the probe 6 4 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com CURRENT TRACING Edge Connectors Shorts between two pins of a row of edge connectors can be detected by connecting the Drive Source as shown in Fig 6 2 DRIVE SOURCE Fig 6 2 Edge Connector Shorts 1 Adjust the Drive Source control to give a reading with the Current Trace Probe at edge connector height 2 Move the Probe down the gap between each connector in turn starting nearest to the Dri
35. gy Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com rtisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 2 DESCRIPTION LOCATING SHORT CIRCUITS WITH THE TONEOHM 850A 2 1 TONEOHM 850A shorts locating modes The TONEOHM 850A provides three shorts locating modes to enable the user to physically locate any type of short circuit without lifting components cutting tracks or otherwise damaging the board under test Millionmmeter This mode will be found highly effective in locating low resistance shorts Track Voltage Trace current flow from the voltage drops caused by the current flowing in a track Used when tracing loading faults and high resistance shorts Current Tracer Use when non contact current tracing is required where access to tracks or components is difficult Milliohmmeter The 850A includes resistance ranges Q and 200MQ which will prove sensitive enough for measuring circuit board track resistance These resistance ranges will prove effective in locating low resistance shorts In many cases short circuits may be pin pointed to within 0 2 inches of actual fault location without the need to disconnect associated components or wiring Higher resistance ranges 20 2000 and 20kQ are included for general purpose resistance measurements Track Voltage Selecting Track Voltage enables current flow to be traced by measuring the
36. he current into the board When Track Voltage ranges are selected the Drive Source output is a DC voltage red clip positive which can be used to stimulate the board under test 2 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com DESCRIPTION Needle probes The Needle Probes are used in all ranges except TRACE The red positive and black negative markings on the probes indicate direction of current flow Track Voltage 2 3 Rear Panel controls and connectors The rear panel accommodates the push button push on push off ON OFF mains power switch and the IEC mains inlet connector 2 4 Mode and range selection Different types of short circuit and loading faults require different location techniques It is often possible to find the fault in more than one way but the following guidelines may prove helpful in deciding the most appropriate shorts locating mode and range In some cases a mixture of techniques may be required When selecting the range to use consider the following questions 1 Is the fault a low resistance short i e less than 200mQ 2 Is the fault static or dynamic l e is the fault always present static or only present when the board is powered dynamic The operator will probably find the Millionmmeter technique most appropriate in locating static low resistance shorts on both single and double sided boards If the fault is dynamic use Track
37. he maximum voltage generated by the Drive Source is 550mV which will not damage devices or turn on silicon junctions The DRIVE SOURCE control is used to adjust the amplitude of the DRIVE SOURCE current The DRIVE SOURCE LED indicates flow of Drive Source current Ifthe LED does not light either the leads are connected incorrectly or there may be insufficient current flowing for the Current Trace Probe to detect the resulting field VOLUME control The VOLUME control varies the sound level of the audible tone Audio tone output The TONEOHM 850A incorporates a variable frequency audio tone output to enable the operator to maintain continuous visual contact with the circuit under test Connectors Headphone socket When the headphones are connected to this socket the internal speaker is switched off and the tone switched to the headphones Use only 3 5mm stereo jack plugs in this socket The TONEOHM 850A is supplied with two sets of probes and Drive Source leads Each probe fits into a unique socket on the front panel Current trace probe and drive source leads The magnetic Current Trace Probe is used to detect currents flowing through tracks components etc without making physical contact The Probe must be used in conjunction with the Drive Source output as it is tuned to the frequency of the AC current supplied by the Drive Source when TRACE is selected The Drive Source leads a pair of red and black clips are used to inject t
38. icalement et l appliquer fermement pour percer l ventuel vernis Il n est pas rare de d tecter des courts circuits entre pistes parall les masqu s par le vernis et dus un cheveu utiliser un scalpel pour couper le court circuit La figure 1 illustre le cas d un court circuit entre la sortie U1 et l entr e de U2 L alimentation de la carte est d branch e et les pointes de touche sont plac es aux points A et E La faible r sistance entre les pistes via le court circuit est visible sur l afficheur et g n re un signal sonore En d pla ant la pointe de touche de A vers B le signal sonore augmente en fr quence et la valeur affich e diminue Cela indique un rapprochement vers le point de court circuit Continuer d placer la pointe pour atteindre une mesure minimum son le plus aigu entre B et C D placer maintenant l autre pointe de touche pour obtenir le son le plus aigu possible d s que la valeur mesur e descend en dessous de 15mQ le son devient discontinu et le point de court circuit est quelques millim tres Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com UTILISATION DE LA MESURE DE TENSION DE PISTE POUR LOCALISER DES DEFAUTS DE SURCHARGE COURT CIRCUIT Fig 1 Court circuit franc UTILISATION DE LA MESURE DE TENSION DE PISTE POUR LOCALISER DES DEFAUTS DE SURCHARGE ATTENTION NE PAS APPLIQUER PLUS DE 50V ENTRE SONDE ET MASSE Le mode TENSION DE PISTE TR
39. iore a 15mohm il puntale si trova a pochi millimetri dal corto circuito e il tono si trasforma in un trillo P_i de Figura 1 Corto circuito a bassa resistenza Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDA PER L UTILIZZATORE UTILIZZO DEL MODO TRACK VOLTAGE PER LOCALIZZARE DIFETTI DI CARICAMENTO Attenzione non superare i 50V tra i puntali e massa Localizzazione di corto circuiti in modo TRACK VOLTAGE Utilizzare questo modo per localizzare la corrente circolante tra le piste misurando la caduta di tensione attraverso la sezione delle piste Il valore visualizzato e il tono corrispondono alla tensione presente lungo le piste solitamente e sufficiente seguire i cambiamenti della tonalita evitando la lettura della misura Nel caso si misurino tensioni negative un trillo provvede ad avvisare l utilizzatore di invertire le polarita Quando si compara il flusso di corrente attraverso le piste mantenere costante la distanza tra i puntali difetti possono essere statici sempre presenti o dinamici presenti solo quando la scheda e alimentata Difetti statici Per i difetti statici togliere l alimentazione dalla scheda sotto test e utilizzare i DRIVE SOURCE per fornire la corrente necessaria a controllare le cadute di tensione lungo le piste della scheda Collegare i DRIVE SOURCE tra i nodi difettosi Utilizzare le portate 20mV e 2mV special
40. iterbahn zu testen schlie en Sie die Drive Source an die fehlerhaften Schaltungspunkte an Verwenden Sie die Bereiche 20mV und 2mV besonders bei breiten niederohmigen Leiterbahnen berlastung der Versorgungsschienen Ein typisches Beispiel daf r ist ein defekter Bauteil der die Versorgungsschiene durch exzessive Stromaufnahme derart belastet da die Spannung zusammenbricht Dies k nnte beispielsweise ein permanenter Kurzschlu zwischen Vcc und GND sein d h ein statischer Fehler In Abb 2 ist Vcc berlastet Wir nehmen an der Fehler sei statisch die Leiterbahnen sind breit d h niederohmig e Schlie en Sie die Anschl sse der Drive Source zwischen Vcc und GND an e W hlen Sie den Bereich 2mV und stellen Sie die DRIVE SOURCE Einstellung auf Maximum e Der StromfluBpfad der Drive Source kann nun verfolgt und der defekte Bauteil aufgefunden werden e Verwenden Sie die Nadelpr fspitzen und messen Sie den Spannungsabfall zwischen A und B Der angezeigte Wert ist 1 257mV und zeigt einen hohen StromfluB e Die Messung des Spannungsabfalls zwischen B und C ergibt einen Wert von 1 118mV und zeigt ungef hr den gleichen Stromflu an e Der Spannungsabfall zwischen den Punkten C und D betr gt nur noch 0 018mV der Strom ist sehr klein Dies bedeutet der Strom in BC mu durch C3 flie en d h der Kondensator C3 ist niederohmig geworden Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www
41. l suono del tono emesso Quando la cuffia e collegata alla presa l altoparlante interno viene disattivato e il tono viene inviato solo alla cuffia Utilizzare solo connettori jack 3 5 mm stereo per questa presa Utilizzo dei puntali del TONEOHM 850A II TONEOHM 850A viene fornito con i puntali a perforazione needle probe un puntale Localizzatore di corrente Current Trace Probe e un set di terminazioni per il forzamento Ogni puntale puo essere inserito un un unica presa del pannello frontale Quando il modo TRACK VOLTAGE e selezionato viene forzata una tensione continua la terminazione clip rossa corrisponde al positivo che puo essere utilizzata per stimolare la scheda sotto test Il rosso positivo e il nero negativo indicati sui puntali indicano la direzione della corrente durante il tracciamento della tensione Quando viene selezionata la funzione TRACE lo stimolo generato e una corrente alternata AC puntali a perforazione sono utilizzabili in tutte le portate eccetto TRACE Collegamento del TONEOHM 850A alla tensione di rete Riferirsi alla tabella delle tensioni presente sul pannello posteriore dello strumento e assicurarsi che corrisponda alla tensione di rete locale Controllare che l interruttore di accensione dello strumento posto sul pannello posteriore sia OFF Inserire il cavo di rete nella presa posta nel pannello posteriore del TONEOHM 850A Inserire la spina in una presa di rete Artisan Technology Group
42. la tension de piste e Connecter les fils source entre le VCC et la masse e Enfoncer la touche 2mV et positionner le niveau de la source au maximum e Suivre le cheminement du courant pour localiser le d faut e A l aide des pointes de touches mesurer la tension entre A et B la lecture 1 257mV indique la circulation d un fort courant e Mesurer la tension entre B et C on lit 1 118mV Ce ci indique un courant environ de m me valeur e Mesurer la tension entre C et D La lecture 0 018mV indique un courant tr s faible absorb par C3 et donc que C3 pr sente une faible r sistance Note Si les fils de la source du 850A avaient t branch s aux bords de C3 toutes les mesures auraient t nulles Si cela arrive connecter un des fils une autre capacit D fauts dynamiques Un autre d faut commun concerne les Cls qui consomment trop de courant et qui entra nent l croulement du VCC Lorsque la carte est hors tension le ph nom ne dispara t C est un d faut dynamique Pour un d faut dynamique la carte est test e sous tension Dans ce cas ne pas connecter la source du 850A Avec l alimentation branch e l op rateur suivra le courant dans les pistes et les diff rents embranchements en mesurant la chute de tension le long des pistes due au courant les traversant NOTE Les lectures ou les carts de moins de 15uV peuvent tre cr s par des tensions thermo lectriques et non par le courant dans la piste Pour cet
43. mV adjustable E EENEG Display 0 7 3 digit LCD lo ii ee Tone Internal speaker headphone socket adjustable volume nr r_1 1t1 1 i ii Detachable ENVIRONMENTAL OPERATING CONDITIONS The instrument is designed for indoor use only under the following environmental conditions Altitude Up to 2000m 5 C to 40 C ambient Relative humidity RH 80 maximum at 31 C derate linearly to 50 at 40 C Mains borne transients As defined by Installation Category Il Overvoltage Category II in IEC664 2 EC664 Pollution Degree 2 IEC664 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL Power Requirements 230V 10 115V 10 or 100V 10 at 50 60Hz 15VA Physical characteristics excluding accessories Dimensions 300 mm 11 8 in wide 110 mm 4 4 in high 260 mm 10 3 in deep Weight 1 5 kg 3 3 Ib ACCESSORIES Standard Accessories Needle Probe set ACC152 Current Trace Probe ACC34 Drive Source Clips ACC33 Operator manual MAN150 SYMBOLS AA CAUTION To prevent damage to this product and to ensure its safe use observe the specifications given in this manual when connecting to terminals marked with this symbol vi Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com GUIDE TO THE MANUAL INTRODUCTION GENERAL DESCRIPTION INSTALLATION AND SET UP
44. mente quando le piste sono ampie ad esempio per resistenze molto basse Sovraccarivo della Vcc Tipicamente i problemi legati al sovraccarico della tensione di alimentazione sono generati da dispositivi difettosi ad esempio dispositivi con bassa resistenza che assorbono corrente in modo eccessivo producendo una bassa resistenza permanente tra Vcc e massa difetti statici In figura 2 la tensione di Vcc e sovraccaricata Assumiamo che si tratta di un difetto statico e che le piste sono ampie bassa resistenza DRIVE SOURCE Cl C2 C3 C4 Ch Figura 2 Misure in modo TRACK VOLTAGE e Collegare la terminazione Drive Source tra Vcc e massa e Selezionare la portata 2mV e predisporre il controllo Drive Source al massimo Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com LOCALIZZAZIONE DELLA CORRENTE CURRENT TRACE SENZA CONTATTAZIONE e Seguire il percorso della corrente del Drive Source per localizzare il dispositivo difettoso e Utilizzando i puntali a perforazione misurare la tensione tra A e B La lettura di 1 257mV indica un elevato flusso di corrente e Misurare la tensione tra B e C La lettura di 1 118mV indica approssimativamente il medesimo flusso di corrente e Misurare la tensione tra C e D La lettura di 0 018mV indica una corrente molto bassa e definisce che la corrente in BC attraversa C3 ad esempio C3 potrebbe avere una resistenza di valore molto basso Occor
45. ni DRIVE SOURCE e Muovendo il puntale tra i connettori 1 e 2 2 e 3 3 e 4 un tono viene generato Quando il puntale viene posizionato tra i connettori 4 e 5 nessun tono viene generato nessuna corrente viene rilevata sul connettore 5 Questo indica che il corto e localizzato sul connettore 4 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDA PER L UTILIZZATORE DRIVE SOURCE Figura 4 Corto circuiti sui connettori piatti Occorre segnalare che se il corto si trova su un connettore vicino alle terminazioni DRIVE SOURCE nessun tono potra essere generato quando il puntale viene spostato tra il connettore 1 e 2 Difetti sul bus nodi circuitali tenuti Il modo TRACE puo essere utilizzato per individuare difetti statici tra due punti che non presentano capacita in parallelo Difetti come un sovraccarico sulla Vcc possono portare a risultati ingannevoli poiche i condensatori in parallelo sulla tensione di alimentazione possono condurre la cor
46. r Drive Source verwendet werden Die Stromst rke der Quelle ist mit DRIVE SOURCE einstellbar Die DRIVE SOURCE LED zeigt einen Stromflu in das Testobjekt an Die Empfindlichkeit der Sonde ist Abh ngig von der Ausrichtung der Spitze Die minimale Empfindlichkeit wird erreicht wenn die schwarzen Linien auf der Spitze zu beiden Seiten quer zur Leiterbahn ausgerichtet werden die das Testsignal f hrt Ein Verdrehen der Spitze um 90 ergibt die maximale Empfindlichkeit Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A KURZANLEITUNG die schwarze Linie auf der Spitze der Sonde zeigt in Richtung der zu testenden Leiterbahn Das Ergebnis ist ein schnell ansteigender Anzeigewert bzw ein rascher Anstieg der Testtonh he Anschlu und Empfindlichkeitseinstellung Die effizienteste Art des Anschlusses ist auf einer Seite der Platine mit einem Abstand der Kabel von 10 20mm Schlie en Sie die Kabel nicht an gegen berliegenden Seiten der Platine an Verbinden Sie die Drive Source Anschlu klemmen mit den kurzgeschlossenen Leiterbahnen und drehen Sie die Stromst rke auf Rechtsanschlag Halten Sie nun die Sonde gegen das Anschlu kabel um eine maximale Empfindlichkeit zu erreichen Drehen Sie nun den Einstellregler der Drive Source zur ck so da auf dem Display ein Wert zwischen 100 und 130 erscheint Ist der Wert kleiner 100 so lassen Sie den Einsteller auf Rechtsanschlag die
47. r niederohmige Kurzschl sse f r Widerst nde unter 200mQ z B bei L tzinn oder Kupferbr cken zwischen benachbarten Leiterbahnen oder L taugen F r dicke Leiterbahnen empfiehlt sich der Bereich Q Dr cken Sie die Pr fspitzen rechtwinkelig mit einem angemessenen Druck auf die Leiterbahn um L tr ckst nde und L tstoppschicht zu durchdringen und testen Sie so die Leiterbahn auf mehreren Punkten Ist der lokalisierte Kurzschlu nicht sichtbar so durchtrennen Sie mit einem Skalpell die Br cke durch die L tstoppschicht hindurch In Abb 1 existiert ein Schlu zwischen dem Ausgang von U1 und dem Eingang von U2 Die Versorgung der Platine wurde entfernt und die Pr fspitzen wurden auf die Punkte A und E aufgebracht Der geringe Widerstandswert zwischen den beiden Leiterbahnen bewirkt eine Anzeige am Display bzw einen h rbaren Ton hervorgerufen durch den Kurzschlu Durch ndern der Pr fspitzenposition von A nach B wird der angezeigte Wert kleiner der Ton wird h her Dies bedeutet die Spitze wurde zum Kurzschlu punkt hin bewegt Wird die Spitze weiter von B nach C bewegt so steigt der angezeigte Wert an der Ton wird wieder tiefer d h die Spitze wurde wieder vom Fehlerpunkt entfernt Der Fehler liegt also zwischen B und C Nun ist die Position der anderen Pr fspitze so lange zu ver ndern bis der Anzeigewert ein Minimum bzw die Tonh he ein Maximum ist Ist der Wert ca unter 15mQ so sind beide Pr fspitzen nur wenige Millimet
48. rce fond dans le sens des aiguilles d une montre Le voyant DRIVE SOURCE s allume indiquant la circulation d un courant dans le court circuit Si le voyant ne s allume pas cela indique soit un mauvais branchement soit un courant trop faible pour tre d tect charge trop lev e Approcher la sonde de courant au dessus d un des fils parall lement sensibilit maxi et r gler le niveau de la source pour afficher environ 100 Ce r glage pourra tre modifi si l on souhaite plus ou moins de sensibilit Mise en oeuvre du traceur Faire attention ne pas d tecter le courant du fil d alimentation au lieu d une piste dans le cas par exemple o la carte recouvrirait le fil Le premier objectif est de trouver la position o les fils de la source peuvent tre branch s de sorte que le courant n est plus d tectable que dans un carr de 15 20mm de cot Le d faut se trouve dans ce carr La m thode la plus efficace est le partage de la carte en diff rentes zones Sectorisation de la carte La meilleure approche est de d placer les points d alimentation de la source autour de la carte pour d tecter dans quelles r gions le courant circule Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDE UTILISATEUR Fig 3 D coupage de la carte e 1 La carte est d abord divis e en quatre secteurs Fig 3 e 2 Brancher les fils source a 10
49. rce und wiederholen Sie den Vorgang e Ver ndern Sie die Einspeisepunkte so lange bis kein Strom mehr aus dem gefundenen Sektor flie t Die Kurzschlu position ist nun in diesem Sektor e Wiederholen Sie den Proze so lange bis der Fehler in einem 20x20mm kleinen Sektor eingegrenzt ist Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com KONTAKTLOSE STROMVERFOLGUNG Abb 3 Board Sectoring Leiterplatten Steckverbinder Kurzschl sse zwischen zwei Pins einer Reihe von Leiterplatten Steckverbindern werden durch die in Abb 4 gezeigten AnschluBart der Drive Source Klemmen lokalisiert e Stellen Sie die Drive Source derart ein da eine Anzeige erscheint wenn die Sonde in H he der Steckverbinder gehalten wird e Folgen Sie der nacheinander der Leiterbahn zwischen den Steckern beginnend bei den Drive Source Anschlu klemmen e Wird die Sonde zwischen den Steckern 1 und 2 2 und 3 bzw 3 und 4 positioniert so ist ein Ton h rbar Zwischen den Steckern 4 und 5 ist kein Ton h rbar d h der Strom erreicht Stecker 5 nicht Der Kurzschlu mu sich also bei Stecker 4 befinden Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A KURZANLEITUNG DRIVE SOURCE 1 2 3 4 5 KURZSCHLUR
50. rch sein Substrat dieser Strom wird durch die Sonde detektiert Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDA PER L UTILIZZATORE INTRODUZIONE II TONEOHM 850A comprende tre modi operativi per localizzare ogni tipo di corto circuito Milliommetro Utilizzando le portate ohm e 2000hm per localizzare corti a bassa resistenza Le portate con resistenza maggiore 2ohm 2000hm e 20kohm sono incluse per generiche misure di resistenza Tracciatore di tensione Utile per individuare la causa del guasto nel caso di piste caricate e TRACK VOLTAGE per corto circuiti ad alta resistenza Utilizzare le portate 2mV e 20 mV per misurare la caduta di tensione lungo la pista in esame generata dal forzamento di una corrente di prova Utilizzare le portate 20mV e 2mV per le piste di maggiori dimensioni Tracciatore di corrente Ricerca di corrente senza un diretto contatto con le piste da CURRENT TRACE utilizzare quando l accesso alle piste o ai componenti risulta difficoltoso Il Localizzatore di corto circuiti TONEOHM 850A comprende un Display a Cristalli Liquidi LCD e un uscita audio con toni a frequenza variabile per l individuazione del corto circuito L uscita Audio permette all Utilizzatore di visualizzare la scheda da controllare senza interruzioni durante l esecuzione delle misure Utilizzo della presa per la cuffia Il controllo del Volume varia il livello de
51. re segnalare che se le terminazioni Drive Source fossero state connesse sopra C3 tutte le misure potevano essere pari a 0 Se questo dovesse accadere la soluzione potrebbe essere trovata muovendo una delle due terminazioni ad esempio su C2 in questo modo puo essere rilevata la caduta di tensione su C3 Difetti dinamici Per difetti di tipo dinamico la scheda deve essere alimentata Non collegare le terminazioni DRIVE SOURCE Il flusso della corrente sara determinato dalla combinazione tra il carico normale e da quello eccessivo generato dal difetto Applicando l alimentazione alla scheda e possibile localizzare il flusso della corrente attraverso le piste e le varie ramificazioni misurando la caduta di tensione lungo le piste NOTA Letture inferiori a 15uV possono essere causate da tensione termoelettriche invece che da piste del circuito stampato L 850A non emette alcuna tonalita per letture inferiori a 50uV LOCALIZZAZIONE DELLA CORRENTE CURRENT TRACE SENZA CONTATTAZIONE NOTA Scollegare l alimentazione della scheda prima di utilizzare il modo TRACE Utilizzo dei DRIVE SOURCE dell 850a I DRIVE SOURCE del TONEOHM 850A applicano la corrente alla scheda da controllare attraverso le terminazioni DRIVE SOURCE una coppia di CLIP rossa e nera e il risultante campo magnetico puo essere rilevato dal puntale CURRENT TRACE Il puntale e accordato alla frequenza della corrente AC generata dai DRIVE SOURCE quando e selezionato il modo TRA
52. rente alternata AC dal DRIVE SOURCE Le linee dei BUS presentano minime capacita e di conseguenza quando occorre isolare un componente che tiene il Bus il modo TRACE consente di isolare velocemente la causa del guasto il difetto viene riscontrato in un circuito di cinque o sei componenti di memoria e possibile utilizzare il Metodo seguente e Collegare le terminazioni sopra le linee difettose e Regolare il controllo del DRIVE SOURCE in modo che il puntale TRACE risponda entro 10 mm di una delle terminazioni DRIVE SOURCE e Passare il puntale sopra ogni componente sospetto con il puntale in parallelo ai pin del componente e componente difettoso potrebbe condurre la corrente generata dai DRIVE SOURCE attraverso il substrato questa corrente puo essere rilevata dal puntale Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com A rtisan Artisan Technology Group is your source for quality Fra op new and certified used pre owned equipment FAST SHIPPING AND SERVICE CENTER REPAIRS WE BUY USED EQUIPMENT DELIVERY Experienced engineers and technicians on staff Sell your excess underutilized and idle used equipment TENS OF THOUSANDS OF at our full service in house repair center We also offer credit for buy backs and trade ins IN STOCK ITEMS www artisantg com WeBuyEquipment 7 EQUIPMENT DEMOS HUNDREDS OF Instra 4 REMOTE INSPECTION LOOKING FOR MORE INFORMATION MANUFAC
53. rige Buchse auf der Ger ter ckseite an Stecken Sie zuletzt den Netzstecker in eine Wandsteckdose Auswahl der Betriebsart und des Testbereichs Wenn Sie einen Bereich w hlen wollen so berlegen Sie folgenden Punkte Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A KURZANLEITUNG e Ist der KurzschluB niederohmig d h kleiner als 200MQ e Ist der Fehler statisch immer vorhanden Verwenden Sie die Milliohmmeter Technik e Ist der Fehler dynamisch nur vorhanden wenn Baugruppe unter Spannung Verwenden Sie die Betriebsart TRACK VOLTAGE Stromverfolgung e Ist der Zugang der Leiterbahnen mit den Testspitzen schwierig so verwenden Sie die Stromfolger Sonde CURRENT TRACE um Str me kontaktlos zu verfolgen e Ist eine Versorgungsschicht in einer Multilayer Leiterplatte kurzgeschlossen so empfiehlt sich die Betriebsart TRACK VOLTAGE Die nachfolgende Tabelle dient als Anleitung zur Bereichsauswahl bei verschiedenen Kurzschlu typen Verwendung versorgt NEIN Tabelle 1 Testbereiche des 850A Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com MILLIOHMMETER LOKALISIEREN VON ZINN UND KUPFERBRUCKEN MILLIOHMMETER LOKALISIEREN VON ZINN UND KUPFERBRUCKEN HINWEIS Entfernen Sie jegliche Versorgungsspannung vom Testobjekt bevor Niederohmige Kurzschl sse Verwenden Sie den 200mQ Bereich f
54. s Under the Return to Factory alternative if a Product is determined not to be defective or to have a defect due to causes not within Polar s reasonable control Polar reserves the right to apply a processing charge 3 Damage in Transit End user must notify Polar and the carrier of any claim for damage in transit within two 2 days of receipt of the damaged merchandise Failure to do so may result in the carrier and or Polar refusing to accept liability in which case end user must pay the purchase price as if the hardware had been delivered without damage 4 Polar s Liability Polar s liability and end user s sole and exclusive remedy shall be limited to the express remedies set forth in this Polar Hardware Warranty 5 Disclaimer of Warranties POLAR MAKES NO OTHER WARRANTIES EXPRESS IMPLIED OR STATUTORY REGARDING PRODUCTS ALL OTHER WARRANTIES AS TO THE QUALITY CONDITION MERCHANTABILLITY FITNESS FOR A PARTICULAR PURPOSE OR NON INFRINGEMENT ARE EXPRESSLY DISCLAIMED 6 Limitation of Liability POLAR SHALL NOT BE RESPONSIBLE FOR DIRECT DAMAGES IN EXCESS OF THE PURCHASE PRICE PAID BY THE END USER OR FOR ANY SPECIAL CONSEQUENTIAL INCIDENTAL OR PUNITIVE DAMAGE INCLUDING BUT NOT LIMITED TO LOSS OF PROFITS OR DAMAGES TO BUSINESS OR BUSINESS RELATIONS WHETHER OR NOT ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES THE FOREGOING LIMITATIONS SHALL APPLY NOTWITHSTANDING THE FAILURE OF ANY EXCLUSIVE REMEDIES Copyright
55. s tritt bei hochohmigen Schl ssen ber 1500 auf Die Empfindlichkeit und damit der Abstand bei dem die Sonde Strom zu detektieren beginnt kann mit dem Einstellregler jederzeit nachjustiert werden Die Funktion von TRACE Achten Sie wenn Sie den Stromfolgermodus verwenden darauf da Sie nicht versehentlich das Feld der Drive Source Anschlu kabel detektieren Wird die Funktion TRACE verwendet so ist das prim re Ziel eine Position zu finden an der die Drive Source Anschlu kabel auf der Platine angeschlossen werden k nnen so da die Sonde kein Feld au erhalb eines 15 bis 20mm gro en quadratischen Felds detektieren kann Dies bedeutet der Fehler mu innerhalb dieses Quadrats liegen Die effektivste Methode ist die Einkreisung des Fehlers durch Sektorbildung Board Sectoring Die erfolgreichste Fehlereingrenzung ist das ndern der Einspeisepunkte der Drive Source um den Sektor einzugrenzen in dem der Fehlerstrom flie t e Die Platine wird zuallererst in vier Sektoren geteilt s Abb 3 e Schlie en Sie die Anschlu kabel der Drive Source im Abstand von 10 20mm nebeneinander nahe einer Ecke der Platine an Sektor 3 in der Skizze e Bewegen Sie die Sonde entlang der Linien AB dann entlang CD um festzustellen ob Strom aus dem Sektor 3 in andere Sektoren flie t Wird Strom auf diesen Linien detektiert so flie t tats chlich Strom in die anderen Sektoren Ist dies der Fall ndern Sie den Anschlu punkt der Drive Sou
56. splay e il tono della frequenza aumentano rilevando la corrente Posizionare il puntale in modo da rilevare la massima lettura in corrispondenza di una delle terminazione DRIVE SOURCE Regolare il controllo del DRIVE SOURCE in modo da ottenere una lettura compresa tra 100 e 130 Se la lettura e inferiore a 100 regolare il controllo allontanandolo dal massimo questo accade quando siamo in presenza di un corto circuito a resistenza elevata ad esempio superiore di 150 ohm Per modificare la distanza oltre la quale il puntale rileva la corrente regolare il controllo del DRIVE SOURCE Operazioni del modo TRACE Quando si utilizzano i puntali nel modo TRACE per seguire la corrente nei circuiti assicurarsi di non rilevare il campo magnetico dalle terminazioni DRIVE SOURCE poste sopra la scheda L obiettivo primario e trovare la posizione delle terminazioni DRIVE SOURCE occorre fare in modo che il puntale TRACE non rilevi il campo generato dalle terminazioni 15 20mm di superficie quadrata intorno alle terminazioni stesse Questo significa che il difetto deve trovarsi al di fuori dall area appena definita Il metodo migliore la divisione della scheda in settori Divisione della scheda in settori L approccio ottimale probabilmente si ottiene muovendo i punti di forzamento del DRIVE SOURCE sulla scheda in modo da determinare in quale regione della scheda la corrente scorre e La scheda viene divisa in quattro settori vedere figura 3 e Collegare
57. strument in ways other than detailed in this manual may impair the protection provided by the instrument and may result in the instrument becoming unsafe Retain these instructions for later use The TONEOHM 850A is designed for use indoors in an electrical workshop environment at a stable work station comprising a bench or similar work surface Use only the accessories e g test probes and clips provided by Polar Instruments The TONEOHM 850A must be maintained and repaired by a skilled electronics technician in accordance with the manufacturer s instructions If it is likely that the protection has been impaired the instrument must be made inoperative secured against unintended operation and referred to qualified service personnel Protection may be impaired if for example the instrument Shows signs of physical damage Fails to operate normally when the operating instructions are followed Has been stored for prolonged periods under unfavourable conditions Has been subjected to excessive transport stresses Has been exposed to rain or water or been subject to liquid spills Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com INTRODUCTION SPECIFICATIONS PE Resistance Ranges Voltage Ranges 2mV 4 15uV Rin 120Q 20mV 4 15uV Rin 120Q 2V 4 15uV Rin 1MQ 20V 4 15uV Rin 1MQ fr i Current Trace Source Oo O Ooo E 0 550
58. te raison le 850A ne g n re pas de signal sonore en dessous de 50uV Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TRACEUR DE COURANT SANS CONTACT TRACEUR DE COURANT SANS CONTACT NOTE Mettre la carte hors tension avant d utiliser la fonction TRACE Utilisation de la source de courant du 850A La fonction TRACE consiste a injecter un courant dans la carte par les fils rouge et noir et a le d tecter avec la sonde de courant par induction Cette sonde est accord e sur la fr quence du signal source et doit donc tre utilis e avec le mode TRACE La tension g n r e est r glable par le potentiom tre DRIVE SOURCE Le LED indique la circulation de courant La sensibilit de la sonde d pend de son orientation La d tection maximum est obtenue en positionnant la sonde parallele la piste le trait noir est au dessus de la piste La sensibilit d cro t en s loignant de part et d autre de la piste Cela s observe par l abaissement du signal La sensibilit est nulle avec la sonde perpendiculaire a la piste Connexion et r glage de la sensibilit La fa on la plus efficace d utiliser la fonction TRACE est de connecter les fils de source loign s de 10 a 20mm l un de l autre viter de les connecter chacun a un coin de la carte Connecter les fils rouge et noir de la source aux bornes des quipotentielles en court circuit Tourner le bouton de contr le de la sou
59. the instrument with the safety earth disconnected Ensure the instrument is connected to an outlet with an effective protective conductor terminal earth Do not negate this protective action by using an extension cord without a protective conductor Note This instrument is fitted with 3 wire grounding type plug designed to fit only into a grounding type power outlet If a special local plug must be fitted to the power cord ensure this operation is performed by a Skilled electronics technician and that the protective ground connection is maintained The plug that is cut off from the power cord must be safely disposed of Power cord color codes are as follows Europe brown live blue neutral green yellow earth ground United States black live white neutral green ground iii Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL POWER SUPPLY Check that the indicated line voltage setting corresponds with the local mains power supply See the rear panel for line voltage settings To change the line voltage settings refer the instrument to a skilled electronics technician Instructions for changing the line voltage settings are contained in the TONEOHM 850A Service Manual published by Polar Instruments TONEOHM 850A OPERATION This manual contains instructions and warnings which must be observed by the user to ensure safe operation Operating this in
60. ttle track is exposed if the milliohm technique proves difficult use Current Trace methods Section 6 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL Example Fig 4 1 illustrates a circuit in which a short circuit exists between the output of U1 and the input of U2 Board power is disconnected and the Needle Probes are placed at points A and E The low resistance between the tracks via the short results in a meter reading and an audible tone Moving the probe from A to B gives a lower reading and a higher tone This indicates that the probe has moved closer to the short Moving the probe from B to C gives a higher reading and a lower tone indicating that the probe has moved beyond the fault This implies that the fault is between B and C Now move the other probe from E to give the lowest reading and the highest frequency tone When the reading is below about 15 mQ the probes should be within a few millimetres of the short and the tone changes to a warble Fig 4 1 Low Resistance Short 4 2 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 5 TRACK VOLTAGE USING TRACK VOLTAGE TO LOCATE LOADING FAULTS CAUTION DO NOT EXCEED 50V BETWEEN EITHER PROBE TERMINAL AND GROUND 5 1 TRACK VOLTAGE shorts locating mode The TONEOHM 850A TRACK VOLTAGE shorts locating mode allows the op
61. up Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com SECTION 7 SIMPLE MAINTENANCE AND CLEANING WARNING This instrument should only be serviced by a qualified electronics technician Refer all servicing to qualified service personnel Polar Instruments publishes a TONEOHM 850A Service Manual to assist the service technician Cleaning Clean the TONEOHM 850A with a cloth lightly moistened with water with a small amount of mild detergent Alternatively a cloth lightly moistened with alcohol ethanol or methylated spirit or isopropyl alcohol IPA may be used Do not spray cleaners directly onto the instrument Technical Support For technical support contact your local Polar Instruments distributor or Polar Instruments Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com rtisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A GUIDE UTILISATEUR INTRODUCTION Le TONEOHM 850A poss de 3 modes de fonctionnement pour localiser tous les types de courts circuits Milliohmetre Utiliser les gammes Q et 200 mQ pour localiser les courts circuits de faible valeur Les autres gammes 2Q 2000 et 20KQ sont destin s a un usage g n ral Tension de piste Sert a la localisation de surcharges et de courts circuits r sistifs Utiliser les gammes 2mV et 20mV pour suivre la circulation de
62. ve Source leads 3 As the Probe is moved between connectors 1 and 2 2 and 3 3 and 4 a tone is generated However when the Probe is moved between connectors 4 and 5 there is no tone showing that no current is reaching connector 5 This indicates that the short is on connector 4 Note that if the short were on the edge connector nearest to the Drive Source leads no tone would be generated when the Probe moved between connectors 1 and 2 6 5 Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com TONEOHM 850A OPERATOR MANUAL Faulty Decoupling Capacitors In certain situations TRACE can help to identify an open circuit decoupling capacitor Fig 6 3 is typical of many circuit configurations A B C D Voc DRIVE SOURCE Cl C2 C3 C4 Ch GND Fig 6 3 Isolation of open circuit decoupling capacitor As the Drive Source is AC in TRACE each capacitor conducts some current The Trace Probe can be used to sense the current flow The display reading and tone give an indication of its relative magnitude The reading noted as the probe is passed over point A would be the highest the sum of four capacitor currents The readings at B C and D would progressively diminish The reading at D would be the lowest only C5 s current If C3 were open circuit the readings at B and C would be equal This method is most suitable for capacitors in the range 0 1uF to 1 0uF 6 6 Artisan Technology Gro

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