FIRING TEST SYSTEM Model 931
Contents
1. 6 1 6 2 Voltage The voltage on the capacitor is calibrated at the factory using a High Voltage Meter with measurement accuracy of 0 10 capable of measuring DC voltage up to 40kV The meter input cable is plugged into the square side of one of the capacitor module selector connectors as shown in Figure 6 0 1 The ground lead is connected to the GND connector located on the rear panel of the Discharge unit The Interlock switch must be closed in order to turn on the voltage Figure 6 0 1 Measuring Voltage on capacitor To perform this measurement the user needs a high voltage meter capable of measuring voltages up to 30kV with a resolution of 10V and a measurement accuracy of at least 0 5 at 25kV Input resistance must be at least 30 000 megOhms Capacitance The actual capacitor value is measured using a capacitance meter The meter input connector is connected to the round side of the capacitor selector connector of the capacitor being measured The other meter lead is connected to the GND connector located on the rear panel of the Discharge unit Total system capacitance is the capacitor value plus the parasitic capacitance Cp of SOpF 30 6 2 The test set up is shown in Figure 6 0 2 Figure 6 0 2 Measuring Capacitance CAUTION Turn off power and make sure all capacitors are totally discharged prior to making this measurement Use the Grounding Cable located on the rear of the Discharge unit b2. 1 Maximum test voltage 25kV 2 Resistors 500 5000 Ohms 3 Capacitor 500pF 2 0 DESCRIPTION The Model 931 FTS shown in Figure 2 0 1 consists of three separate components 1 Control Unit 2 Discharge Unit 3 Firing Test Chamber Optional FIRING TEST SYSTEM TRIGGER MODE DISCHARGE CONTROL DISCHARGES i E E i VW EJ AGE DISCHARGE CHARGING VOLTAGE POSITIVE POLARITY EG a Control and Discharge units b Firing Test Chamber Optional Figure 2 0 1 Model 931 Firing Test System The principle of operation of the Model 931 is illustrated in Figure 2 0 2 HIGH VOLTAGE EE POWER SUPPLY v TEST DEVICE W LIMITING GE RESISTOR 25M H V LEVEL RANGE ADJUST DIGITAL PANEL METER JUNCTION BOX DISCHARGE INTERVAL PONT eo CAPACITOR ADJUST amp TIMING TRIGGER CONTROL ARM PIRS DISCHG OPT Figure 2 0 2 Simplified Block Diagram The standard Model 931 Firing Test System is housed in two 2 units A Control Unit that contains the low voltage power supply discharge control and timing circuits and the operating controls A Discharge Unit that contains the high voltage power supply Polarity Reversing Module R C networks and the HV SPDT gas filled relay In the standard configuration the two units are interconnected by a detachable 10 3m long 15 pin sub D cable and a 12 30 5cm ground wire Each unit is housed in an aluminum enclosure measuring 16 5 Wx3 5 Hx12 D 42 6x8 8x
3. and system capacitance of better than 15 for capacitors 500pF and below and 5 for capacitors 1000pF and above High Voltage resistors with a 5 or better tolerance are used The following are typical actual system capacitance and resistance values SPECIFIED ACTUAL RO C pf RO C pf 900 100 490 107 1500 250 1526 257 5000 5000 5006 4970 The energy stored in the system is calculated using the following formula E C C 1 V Joules or E ach Joules 19 3 2 3 3 Cp2 is the parasitic capacitance of the cable and accessories plugged into the output connector For the standard configuration this capacitance is approximately 60pF This capacitance affects the discharge waveform characteristics such as peak voltage rise time and ringing The lower the capacitor and the higher the discharge resistor used the greater the affect on the initial ringing observed on the discharge pulse For 500pF and 500 Ohms this appears as overshoot For 500pF and 5000 Ohms this appears as high frequency ringing Refer to Figures 6 0 5 and 5 When the optional Junction box is used Cp2 increases to approximately 100pF at the output and when 1m tests leads are attached Cp is approximately 110pF Charging Voltage The voltage applied to the capacitor is adjusted at the factory to be better than 2 over the entire voltage range However as capacitance decreases the effect of parasitic capacitance increases due to the relative closeness in v
4. 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 CHARGING TIME s Figure 2 0 3 Exponential charging curve 2 1 Control Unit 2 1 1 Front Panel Figure 2 1 1 shows the Control Unit front panel FIRING TEST SYSTEM CHARGING VOLTAGE DC KILOVOLTS at Figure 2 1 1 Control Unit front panel 2 1 1 1 A C Power ON OFF This rocker switch controls the AC power input to the unit When power is on the LED Charging Voltage Meter and either the HI or LO RANGE light will light Figure 2 1a shows the installation of an optional key switch for controlling access to the system AC POWER KEY SWITCH secure keys Figure 2 1 1a Optional AC Power key switch 2 1 1 2 DISCHARGES SELECT Switch This ten 10 position rotary switch is used to select the number of discharge pulses the System will produce when the system is in the AUTO COUNT mode When the DISCHARGES SELECT switch is in the O position the unit will be inhibited from producing discharge pulses regardless of the position of the DISCHARGE switch When set to position 1 the system will produce only one 1 pulse each time the DISCHARGE switch is activated thus making controlled single shot operation possible The DISCHARGES SELECT switch setting is over ridden when the AUTO COUNT FREE RUN switch is in the FREE RUN position 2 1 1 3 AUTO COUNT FREE RUN SELECT Switch This 2 position toggle switch programs the system for either FREE RUN or AUTOMA
5. PC_ 4 Safety Interlock Cable e D GNDCable ___ 6725 MIA IN BG Gasket 25x 25 Buna N McMaster Carr 9700K14 En ES O S E Powder Dise SS Powder Cups 6628 EAN es Needle Electrodes Keystone Elec 3014 KEE _ E a 1 AlligatorClip Keystone Elec 504 2 BananaPlug Red Keystone Elec 6078 A Black o keystone Elec 6078 4 JunctionBoxs 6818 _ S po BV Plug 930A Plug Alden Products A601 oo BananaJackRed _ Keystone 6078 ob Bananadack Bik POTD Y Safety Discharge Cable 6724 II Test Target o o O O 1 20dbAttenmuator Meca Electronics 612 20 1 pier eS eamm E Male Cambridge A e AA Plug A Adapter SMA Female to BNC 1 Amphenol Connex 242103 500 Terminator Cal Test Electronics CT 2944 10 13 41 8 0 WARRANTY Electro Tech Systems Inc warrants its equipment accessories and parts of its manufacture to be and remain free from defects in material and workmanship for a period of one 1 year from date of invoice It will at it s discretion either replace or repair without charge F O B Glenside similar equipment or a similar part to replace any equipment or part of its manufacture which within the above stated time is proved to have been defective at the time it was sold All equipment claimed defective must be returned properly identified to the Seller or presented to one of its agents for inspection This warr
6. To reset the instrument must be powered down for 10 seconds before turning the power back on As an additional safety measure an external replaceable fuse is also installed Replace this fuse only with one having the required current rating voltage and specified type such as normal blow slo blo time delay etc DO NOT use makeshift fuses or short the fuse holder This could cause a shock or fire hazard or severely damage the instrument POWER LINE VOLTAGE MAINS If the line mains voltage is changed or isolated by an autotransformer the common terminal must be connected to the ground earth terminal of the power source OPERATION CAUTION Equipment designed to simulate a high voltage electrostatic discharge such as the series 900 ESD Simulators and the Model 4046 Static Decay Meter utilize voltages up to 30kV The basic nature of an ESD event will result in electromagnetic radiation in addition to the high level short duration current pulse Therefore personnel with a heart pacemaker must not operate the instrument or be in the vicinity while it is being used DO NOT OPERATE WITH COVERS OR PANELS REMOVED Voltages inside the equipment consist of line mains that can be anywhere from 100 240VAC 50 60Hz and in some equipment voltages as high a 30kV In addition equipment may 1 contain capacitors up to 0 035 uF charged to 30kV and capacitors up to 0 5 uF charged up 6kV Capacitors can retain a charge even if the equipment is turn
7. Total number of samples use 1000 Current increments 1000 from waveform INSTALLATION The Model 931 Firing Test System has switching power supplies that operate from 90 260VAC 50 60Hz No line voltage mains selection is necessary 21 These power supplies incorporate resettable fuses To reset turn off the unit for at least 20 seconds then turn it back on If the system still does not operate contact ETS at 215 887 2196 for service For additional safety a 3AG 250V 3 4amp Slo blo fuse is located on the rear panel The input power connector accepts the standard IEC 3 wire power cord The System must be plugged into a grounded power mains outlet The standard System is supplied with a North American grounded power cord Other power cords can be provided if specified at time of order These cords are standard items typically used for computers TVs etc and the appropriate one can be obtained by the user locally However if the correct power cord is not available the plug on the supplied cord can be cut off and the correct plug installed The BLACK wire is the HOT lead the WHITE wire is neutral and the GREEN wire is ground Power Key Switch Optional A key switch can be installed to restrict use of the Model 931 to authorized personnel If this option is a retrofit it will be installed on the rear or right side panel and will be connected in series with the existing front panel rocker switch However if specified at ti
8. a function of the R C network used and is calculated using t RC 1 time constant 37 NOTE As capacitance is reduced the peak pulse measured is also reduced due to the effects of the stray capacitance The above also holds true for resistances below 500 Ohms Below 500 ohms the impedance of the circuit begins to limit the maximum current obtainable At 150 Ohms the waveform starts to take on the characteristics of the 0 Ohm waveform As the discharge resistance is increased it begins to form a tuned circuit that appears as a sharp initial spike in the first 20 nsec and then ringing over approximately the next 50 nsec It is most noticeable at capacitances below 500pF and resistances above 1500 Ohms Ringing is also affected by the length of the output cable Testing explosives is based on energy levels which is the area under the curve of the discharge waveform Using the actual Capacitance and current waveform levels will enable the user to accurately calculate the desired energy levels The calibration waveforms supplied with each unit shows the full waveform and is that portion that constitutes virtually all the energy contained in the discharge The peak current listed ignores the initial short duration overshoot and high frequency ringing observed The discharge energy can be calculated using the following formula E Rt 2 I Where R Discharge Resistance 500 or 5000Q t Time between samples use time base setting on scope n
9. network Plug the RESISTOR SELECTOR module into the respective resistor value connector and the CAPACITOR SELECTOR module into the appropriate capacitor value connector For units with plug in resistor modules the required resistor is plugged into the lower right hand connector labeled RESISTOR For units with built in resistors plug the RESISTOR SELECT module into the appropriate resistor connector in the bottom row NOTE If the system is configured with both internal and plug in capacitor modules either the SELECTOR or the appropriate capacitor resistor module should be used but NOT BOTH Make sure the modules are seated all the way 4 Select the desired voltage range For voltages up to 5kV move the RANGE switch to the LO position Green LED The LO range output is 100 5500V For voltage levels above 5kV set the RANGE switch to the HI position Red LED The HI range output is 3 26kV The interlock switch must be closed to activate the high voltage For the Firing Test Chamber the door must be fully closed and latched NOTE The Model 931 is capable of charging capacitors up to 0 02uF 20 000pF to 26kV For those specifications requiring larger value capacitors the maximum voltage specified is 5kV Mil Std 1751A Method 1031 The Discharge Unit incorporates an interlock system that locks out the Hi range to limit the maximum voltage applied to capacitors higher than 0 02uF to the LO range 5 5kV Pu
10. received The Interval control does not function when remote triggering is used 2 1 1 8 2 RANGE INDICATORS These point source LED s indicate the voltage range selected The Green LED indicates the LO Range and the Red LED indicates the HI Range CHARGE DISCHARGE Indicators These two LED point source indicators illuminate during the appropriate portion of the Charge Discharge cycle The Red CHARGE indicator will be illuminated when the ARM switch is in the ARM position The Yellow DISCHARGE indicator will light during the brief discharge time Failure of either indicator to light at the appropriate time may be an indication of a system malfunction CHARGING VOLTAGE Meter This 4 digit LED meter indicates the magnitude and polarity of the charging supply voltage directly in Volts in the LO range and in kiloVolts kV in the Hi range The meter reading is the voltage applied to the selected capacitor and is related to the magnitude 12 A A 2 2 of the discharge pulse produced when the DISCHARGE switch is activated The energy stored in the capacitor bank may be calculated using this meter reading The energy will be equal to CN where C is the value of the storage capacitor plus parasitic system capacitance and V is the charging voltage as indicated by the meter 2 1 2 Rear Panel The rear panel shown in Figure 2 1 2 contains the IEC input power mains power connector fuse holder for a 3AG style fuse ground terminal
11. that accepts either standard 162 banana plugs or wire ends and a 15 pin sub D control signal connector The optional TTL BNC input connectors for ARM and DISCHARGE are also located on this panel ets oem systems inc Sut FLAT AA ma ic cl MAT UA G TEST SYSTEM CONTROL UNIT o O REMOTE TRIGGER REMOTE ARM TTL 3V to 15V TTL 3V to 15V DURA gt us on when TTL on To FUSE DISCHARGE Gi 24 AMP Figure 2 1 2 Control Unit rear panel Discharge Unit 2 2 1 Front Panel The front panel layout with the standard System D R C network select is shown in Figure 2 2 1a and the standard R C and selector modules are shown inn Figure 2 2 2 E eae DURE Figure 2 2 1 Discharge Unit front panel layout At high voltage corona may develop inside the capacitor select connectors Safety plugs as shown in Figure 2 2 1 that plug into unused connectors are now supplied as standard 13 5000 Figure 2 2 2 Standard selector and R C modules This unit contains the High Voltage Power Supply Polarity Reversing Module R C network components 35kV High Voltage Relay and an internal 25 megOhm bleeder resistor connected to the output connector NOTE Without a firing voltage will remain on the capacitor A 25 megOhm high voltage bleeder resistor is incorporated at the discharge output connector This will enable the charge to bleed off when the DISCHARGE switch is depressed However when using a Firing Tes
12. the discharge cycle must be operated manually For example to charge the 0 25uF capacitor to the desired voltage requires approximately 90 seconds 2 1 1 8 DISCHARGE CONTROL 2 1 1 7 1 ARM This spring loaded toggle switch is used to turn the High Voltage on When depressed it is in the ARM position and the voltage will be displayed on the meter and the red LED will light This switch must be in the ARM position to perform a test When charging capacitors greater than O2uF the time to reach full charge becomes quite long To speed up the charging time set the voltage to maximum 5 5kV and when the meter indicates the desired test voltage activate the DISCHARGE switch Remote TTL ARM Control Optional When installed an external TTL signal controls a relay that parallels the ARM and Discharge switch and will automatically charge ARM the capacitor then initiate a discharge when a second TIL signal is received The Interval control does not function when remote triggering is used The charging time required for C 0 25uF is approximately 90 seconds and several minutes for C 0 5uF when the charging voltage is set to the desired voltage This can be overcome by first setting the charging voltage above the desired value as shown in Figure 2 0 3 and then determine the time required for the capacitor to charge up to the desired voltage The TTL pulse timing is then set to trigger the discharge relay at the established time The higher t
13. to pins Gnd to case 40kV Wire Firing Test Box Wall 40kV Wire Junction Box Dischg Input Gnd Wire Firing Test Box Wall Figure 5 0 1b DUT wiring connections Output to case Gnd to pins If the discharge current waveform is to be monitored using the Model 949 Test Target connect the OUTPUT wire to the desired pin or location on the DUT Connect the GROUND side of the DUT to the Test Target input banana jack as shown in Figure 5 1 2a and b The DUT will be connected to ground through the 2 Ohm Target resistance A typical set up is shown in Figure 5 0 3 24 Junction Box Socket Dischg Input 40kV Wire Firing Test Box Wall To Scope Input Test Target Input Figure 5 0 2a DUT current waveform monitoring connection Output to pins Gnd to case 40kV Wire Junction Box Socket Dischg Input Gnd Wire Firing Test Box Wall To Scope Input Test Target Input Figure 5 0 2b DUT current waveform monitoring connection Output to case Gnd to pins Figure 5 0 3 Typical current monitoring test setup with Junction Box 25 2 If the ETS Firing Test Chamber is installed close the Firing Test Chamber door and lock it in place by moving the handle from left to right The interlock switch will only be activated when the door is fully closed For other test locations or chambers install the interlock cable and follow established procedures 3 Select the desired R C
14. 005 13 30 19 13 34 21 10uF 250V Tek Run 20MS s Sample MEF ch1 Min 7 2 V 50uF 250V Figure 6 0 6 Discharge waveforms for MIL STD 1731A Method 3031 7 0 MAINTENANCE As with any electronic equipment a circuit could fail at any time The most efficient way to handle this type of failure is to contact ETS describing the problem ETS can then offer a course of action to fix the problem as soon as possible Most electronic failures usually occur with an IC failure All IC s in the Model 931 are mounted in plug in sockets and should be readily available from electronics distributors or can be obtained from ETS Warranty items will be supplied by ETS 38 1 1 Access to the Control and Discharge units can be obtained by first removing the top cover lt is held in place by 6 4 40 x A screws Pull the cover up to remove Prior to removing the cover from the Discharge unit first make certain that the internal capacitors are discharged by connecting the supplied grounding wire to the round pin of all capacitor select connectors to bleed off any residual charge that may be on the capacitors CAUTION DANGEREOUS VOLTAGES CAN REMAIN ON THE CAPACITORS FOR A SIGNIFICANT AMOUNT OF TIME AFTER THE SYSTEM HAS BEEN TURNED OFF EVEN THOSE CAPACITORS NOT DIRECTLY CHARGED DURING THE LAST TEST NOTE Firing Test Chamber Some items in the Firing Test Chamber could possibly be damaged during a test Parts damaged during a fi
15. 30 5cm NOTE If the two units need to be separated additional control cables can be connected in series and an appropriate length ground cable fabricated to obtain the necessary cable lengths The recommended maximum length is 4 10 3m cables The CHARGE DISCHARGE cycle is accomplished using a 35kV SPDT gas filled relay In FREE RUN the System will continue to produce discharge pulses as long as the ARM and DISCHARGE switches are held down The dwell time or charging period between discharge pulses Is adjustable by the user from 1 3 second to about 10 seconds In AUTO COUNT the user selects the number of discharge pulses desired 1 to 9 and then depresses the ARM and DISCHARGE switches The FTS will then produce the selected number of pulses at the selected time interval between pulses A single digit numeric readout displays the number of pulses produced from 1 9 When the DISCHARGE switch is released the system counter resets to zero and the production of HV output pulses stops The discharge pulse sequence is repeated each time the DISCHARGE switch is activated AUTO mode is only useable for capacitors up to 0 02uF because of the charge up time required for higher value Capacitors Remote TTL Trigger Inputs ARM amp DISCHARGE Optional factory installed This option parallels the function of the ARM and Discharge switches It allows the user to both ARM and trigger the discharge relay using an external source such as a co
16. FIRING TEST SYSTEM System shown may differ from actual system ordered Operating Manual 10 13 electro tech systems inc 3101 Mt Carmel Avenue Glenside PA 19038 Tel 215 887 2196 Fax 215 887 0131 IMPORTANT SAFETY INSTRUCTIONS Equipment containing HV The equipment described in this Manual is designed and manufactured to operate within defined design limits Any misuse may result in electric shock or fire To prevent the equipment from being damaged the following rules should be observed for installation use and maintenance Read the following safety instructions before operating the instrument Retain these instructions in a safe place for future reference POWER POWER CORD Use only the power cord specified for this equipment and certified for the country of use lf the power mains plug is replaced follow the wiring connections specified for the country of use When installing or removing the power plug hold the plug not the cord The power cord provided is equipped with a 3 prong grounded plug a plug with a third grounding pin This is both a safety feature to avoid electrical shock and a requirement for correct equipment operation lf the outlet to be used does not accommodate the 3 prong plug either change the outlet or use a grounding adapter FUSES The Model 931 utilizes switching power supplies that operate over the voltage range of 90 260VAC 50 60Hz These units incorporate resettable fuses
17. TIC operation When this switch is in the FREE RUN position the DISCHARGES indicator is off not illuminated and the system will continue to produce discharge pulses as long as the TRIGGER switch is depressed When in the AUTO COUNT position the DISCHARGES display will be illuminated and the System will produce the number of discharge pulses programmed by the setting of the DISCHARGES SELECT switch each time the DISCHARGES switch is activated 1 9 If more than 9 discharges are required the sequence is repeated until the total number of discharges are reached NOTE The AUTO COUNT mode should not be used for multiple counting in the HI RANGE when the output resistor is 0 Ohms 2 2 1 4 2 1 1 6 2 1 1 7 TTL trigger Optional When installed the TTL signals will control the number and interval of the pulses desired The AUTO mode for pulses more than 1 single shot cannot be used with the TTL option since the Auto mode is controlled by internal charge discharge timing circuits RANGE This 2 position toggle switch selects either the LO or the HI Range In the LO position the usable voltage range is approximately 100 V to 5 5 kV and in the HI position the usable voltage range is approximately 3 to 26kV When high value capacitors gt 0 02uF 20 000pF are used they have a voltage rating of 6 8 kV Whenever these capacitors are selected the HI RANGE is locked out so only a maximum of 5 5 kV can be applied to these capacit
18. ___ A pC IC 14 Pin 4071 0090 00018 ON Semiconductor MC14071BCPG po 4081 0090 00042 ON Semiconductor MC14081BCPG po 4511 0090 00043 ON Semiconductor MC14511BCPG po 4520 0090 00044 ON Semiconductor MC14520BCPG po L723 0090 00723 Texas Instrument LM723CN MOPB NO NO O O Ql Transistor 2N3904_ Q2 3 5 13 Fairchild Semicond 2N3904TFR_ A 2N8906 4 6 Fairchild Semicond 2N3906TAR po TPAC 1 8 14 Fairchild Semicond TIP31C TIL CktBd_ IC LM556 UP S O pi Diode 1N4148 1 2 Vishay Semicond 1N4148 TAP Relay DPST DISCH ARM 40 MA LA IS PETT O S y O 1 Capacitor Banks pF 250 6810 o ooo 2 3 Capacitor Banks uF O pT HL 0 02 6809B Bycap 6B303 303A___ E E AENA EE ES 6 HighVoltageComnectors 0032 00501 Alden Products E201QX12 7 LV Driver 0112 00001 enee ff 9 HV Polarity Reversing Module 5516 10 HV SPDT 35kV Relay 00041 Lee K61 Lesen 00002 12 Selector Modules C amp Inter R 6813 LI 13 ResistorModules External R 6814 15 Discharge Output Cable std 6815 16 Discharge Output Cable FTC ong LI 7 Discharge Output Cable Cust 6817 J 9 _25MegOhmHVResistor___ Dale ROX2F 25M Accessories d S Firing Teste 1 Safety Interlock Switch Globteck MPOO31 A 5 PinDIN Interlock Cable Con Switchcraft 502 57HBSF 93 ToggleLatch CarrlaneMfg CL 300
19. a third conductive body or to each other the built up static charge will flow from one body to the other in a short time The resulting net charge build up will be zero If on the other hand if these same charged objects are separated by an insulator the charge build up may not be neutralized and each body may retain its charge for a long time particularly in a low humidity environment The charging of objects due to relative motion is known as the Triboelectric Effect It can produce voltages from a few volts to tens of thousands of volts The charge build up depends on many factors including the amount and rate of motion the composition of the materials involved the secondary surfaces involved floor table top air etc the relative humidity level of the air surrounding the charged bodies and surface coatings used on any of the surfaces if any When a highly charged body is brought near a neutral body or one that has an opposite charge a rapid discharge can occur In many cases this discharge is nothing more than an annoyance however under the right circumstances it could contain sufficient energy to ignite an explosive product mixture or activate an explosive device such as initiator used in automotive military and space applications One of the most common types of electrostatic build ups occurs with the flow of people and material over nonconductive surfaces Humidity conditions usually determine how static dissipative a surface i
20. alue Above 1000pF the effect becomes insignificant The output voltage pulse measured will be less than the DC voltage applied to the capacitor by approximately Vm CV C Cp1 Discharge Pulse Calibration The output pulse is calibrated using an IEC 61000 4 2 compatible test target ETS Model 949 as shown in Figure 3 3 1a The Model 949 is also available installed in the Firing Test Box shown inf figure 3 31b This method is specified for most Human Body Model applications and is referenced in MIL STD 331C There is no output waveform calibration method specified for the other common explosive device discharge networks a External Test Target b Test Target installed on Firing Test Box Figure 3 3 1 Test Target installions 20 4 0 The Model 931 output is calibrated using the current waveform method The ETS Model 949 Test Target and an Agilent Model DSO6102 1 GHz oscilloscope are used to calibrate the System However any oscilloscope having a bandwidth of 200MHZz or better is satisfactory Typical waveforms for several networks are shown in Figures 6 0 4 amp 5 Actual waveforms for the specific 931 System are supplied separately as part of the System Calibration The output waveform using discharge resistors is calibrated to produce a discharge pulse having the correct E IR 10 relationship i e a 5kV pulse through a 500 Ohm resistor should have an average peak current value over the first 50nsec of 10 1 Amps Fall time is
21. anty only applies to equipment operated in accordance with Seller s operating instructions Seller s warranty with respect to those parts of the equipment that are purchased from other manufacturers shall be subject only to that manufacturer s warranty The Seller s liability hereunder is expressly limited to repairing or replacing any parts of the equipment manufactured by the manufacturer and found to have been defective The Seller shall not be liable for damage resulting or claimed to result from any cause whatsoever This warranty becomes null and void should the equipment or any part thereof be abused or modified by the customer of if used in any application other than that for which it was intended This warranty to replace or repair is the only warranty either expressed or implied or provided by law and is in lieu of all other warranties The Seller denies any other promise guarantee or warranty with respect to the equipment or accessories and in particular as to its or their suitability for the purposes of the buyer or its or their performance either quantitatively or qualitatively or as to the products that it may produce The buyer is expected to expressly waive rights to any warranty other than that stated herein ETS must be notified before any equipment is returned for repair ETS will issue an RMA Return Material Authorization number for return of equipment Equipment should be shipped prepaid and insured in the original pa
22. apacitance values are specified the following individual R and C values are supplied for System A R Ohms C pF 0 500 500 1000 5000 2000 5000 These resistors are generally installed internally However for System D Method 1751A configuration the resistors are external and are installed inside individual plug in modules When networks are installed internally a selector module is used to connect the respective network to the charge discharge circuit When external modules are used they plug into the RESISTOR connector To achieve the 100pF specified a separate capacitor module labeled 100pF is inserted into the 250pF slot to convert the 250pF to 100pF Unused connectors if installed are not connected internally and are used to store network modules only They are labeled NOT USED Figure 2 2 1 shows various configurations The MIL STD 1731A Discharge unit System D contains all the capacitors and the 0 Ohm plus 500 and 5000 Ohm resistors specified in Methods 1031 1032 and 1033 The test voltage is limited to lt 6 kV for capacitors greater than 0 02uF Method 1034 is optional and requires a special triple Capacitor Select Module that combines the 5 10 amp 20 000pF 0 005 0 01 amp 0 01uF capacitors to achieve the 35 000pF specified 2 2 2 Rear Panel The rear panel shown in Figure 2 2 3 consists of the 15 pin sub D control signal input ground safety interlock and high voltage discharge output connectors pl
23. ated at 1kW for pulses SMA BNC cable and 50 Ohm Terminator to connect to the 1 megOhm input of the scope The 50 Ohm terminator supplied MUST be used Otherwise the waveform measured will be approximately twice the actual amplitude The conversion factor of the Test Target is 1 1 and with the attenuator 10 1 That is 1 Volt measured on the scope is equivalent to 1 Amp and 10 Amps respectively Note Cable is coiled for illustration purposes only Figure 6 0 3a Current pulse calibration set up external Test Target 32 Figure 6 0 3b Current pulse calibration set up Firing Test Chamber installation The waveform is captured using the appropriate scale for the voltage level and resistor value being measured and the appropriate time base that will range from 25 nsec div to 10 usec div depending on the R and C values Refer to Figure 6 0 4 for appropriate scope setting for the particular RC network being measured Rise times are typically 10 25 nsec The discharge waveform is displayed to look at the area under the curve that is used for the energy calculation R C networks using low Capacitance lt 1000pF and high resistor values 5000 Ohms will exhibit a large overshoot then ringing over the first 25 nsec or so This ringing increases with output cable length and constitutes only a very small area under the discharge curve and has very little effect on the overall energy under the full curve The average peak voltage over the fi
24. cally once the TTL signals are received 2 6 After a test has been completed wait until the reading on the meter is lt 100V then open the door by moving the handle to the left The interlock switch will open preventing the HVPS to turn on even if the ARM switch is activated The discharge circuit incorporates a safety 25 megOhm resistor to ground at the discharge output connector inside the Discharge Unit This resistor is in the circuit to bleed off any residual charge that may remain after a discharge The output circuit that is the circuit holding this charge is basically Cp2 which is approximately 25pF for the Firing Test Chamber device test circuit Other configurations can increase Cp2to 100pF or more The time to bleed off the residual charge is t 5RC 5x100x10 Qx25 x10 pF 0 125 sec 125 milliseconds Other output configurations could have significantly higher residual Capacitance CAUTION IT IS UP TO THE USER TO DETERMINE THE PROPER SAMPLE SIZE OF A GIVEN TYPE EXPLOSIVE THAT WILL SAFELY IGNITE IN THE MODEL 931 FIRING TEST CHAMBER 5 2 Device Testing To test devices connect the Output lead Red banana plug to the desired pin or other connection of the DUT and the Ground lead Black banana plug to the ground connection or shell of the DUT If it desired to monitor the discharge waveform two methods can be used The preferred method is to connect the ground side of the test circuit to the input of the ETS Mod
25. ckaging If the original packaging is not available the equipment must be packed in a sufficiently large box or boxes if applicable of double wall construction with substantial packing around all sides The RMA number description of the problem along with the contact name and telephone number must be included in formal paperwork and enclosed with the instrument Round trip freight and related charges are the owner s responsibility WARNING WOODEN CRATES MUST NOT BE USED TO PACKAGE THE ELECTRONIC UNITS PACKAGING OF DELICATE INSTRUMENTS IN WOODEN CRATES SUBSTANTIALLY INCREASES THE CONTENT S SUSCEPTIBILITY TO SHOCK DAMAGE DO NOT PLACE INSTRUMENTS OR ACCESSORIES INSIDE OTHER INSTRUMENTS OR CHAMBERS ELECTRO TECH SYSTEMS INC WILL NOT ASSUME RESPONSIBILITY FOR ADDITIONAL COST OF REPAIR DUE TO DAMAGE INCURRED DURING SHIPMENT AS A RESULT OF POOR PACKAGING 42
26. ct 2005 09 09 23 Tek Run 10MS s Sample IBER E tant F GE 3 Oct 2005 09 09 23 Discharge waveform 5kV C 2000pF Figure 6 0 4 Typical discharge waveforms 5kV 35 Tek Run 16575 Sample Ip See ee E E j Tek Run 200MS s Sample IGRE E oe gee TF S Dip EE F V 30 Sep 2005 3 Oct 2005 15 39 54 09 13 23 Discharge waveform 25kV C 100pF Tek Run 500MS s m Trig Tek Run 50MS s Sample DPE a WEEN Er CR Mi0 ns Chi 7 amp 8 chi Tv M ips chi 7 1 24V 30 Sep 2005 3 Oct 2005 16 04 09 09 18 27 R 5000 R 50000 Discharge waveform 25kV C 500pF Tek Run 100MS s a MEE Tek Run 10MS s Sample IEE Enea E es w E E e E WE V 30 Sep 2005 16 14 10 Waveform 25kV C 2000pF Figure 5 0 5 Typical discharge waveforms at 25kV 36 Typical waveforms for the Method 3031 discharge unit are shown in Figure 6 0 6 NOTE When measuring these waveforms the current pulses can be very high This will require an attenuator with a peak power rating of at least 1kW Most standard attenuators are rated at 2 Watts continuous The waveforms shown in Figure 6 0 4 were taken at 1000 500 and 250 Volts in order to be within the measurement range of the oscilloscope used The discharge waveforms are linear and therefore can be extrapolated out to the required 5kV test voltage Tek Run 200MS s Sample IEEE s chi Freq 9 427MHz Chi Period Soe BE A sodas A de ea
27. e 1 106 1ns Oct 2005 WIRE 100pf 5kV Tek Run 200MS s Sample Gt E e EEN E chi Max 20 Y ch1 Min 14 Y kt Ee 3 109MH2 Ch1 Period i 321 75 19 Oct 2005 13 05 36 Ki O 1kV Tek Run 200MS s Sample E EF x 4 Ch1 Max 39 6 Y ch1 Min 28 Y Ch1 Freq 1 402MH2 Chi Period Sg 713 3n5 3 Tek Run 200MS s Sample DEEK Ch1 Max 39 2 V ch1 Min 34 4V ch Period 216 7ns5 att HT OY 500pf 2 5kV Oct 2005 02 00 Tek Run 200MS s Sample DEEE GE Max JI Chi Period l 476 25 19 Oct 2005 13 08 31 2000pF 1kV Tek Run 1 0OMS s Rane 4 Ch Max i 26 8 ch1 Freq 1 008M1Hz Chi Period 992 505 AT 500ns chi FV t 2005 9 ch zc wie 0 ao un 5000pF 1kV 01uF 500V de Tek Run 100MS s Sample GRR AAA AAA E EE EE DE NN i E E ARA O Ge en Lef A AN O nee Si ch1 Max ale o ee ay 24 Y ch1 Min E i me hi Min Sack F A a A e a Ne as 24 Y 12 4 Y a A E AI A A DEE d chi Freq z chi F i 720 7kHz 470 2kHp Ch1 Period Ch1 Period ey nga ave eee E A A ED es A A 1 38745 aea A E AA A e te 2 145 NU iN Mav ns Chi 10 Y MN ov M500ns Chi F 10V Oct 2005 27 0 19 13 Chi Max Chi Max 32 8 V 43 4 chi Min chi Min eh E 10 6 VY Ae CH1 Freq 304kHz Chi Period A O A aed II A Roh at 3 2945 hh AR Y RES ER OUR GA Y A As CAT FAT 19 Oct 2005 19 Oct 2
28. ed off DO NOT OPERATE WITH SUSPECTED EQUIPMENT FAILURES If any odor or smoke becomes apparent turn off the equipment and unplug it immediately Failure to do so may result in electrical shock fire or permanent damage to the equipment Contact the factory for further instructions DO NOT OPERATE IN WET DAMP CONDITIONS If water or other liquid penetrates the equipment unplug the power cord and contact the factory for further instructions Continuous use in this case may result in electrical shock fire or permanent damage to the equipment DO NOT OPERATE IN HIGH HUMIDITY Operating the equipment in high humidity conditions will cause deteriation in performance system failure or present a shock or fire hazard Contact the factory for further instructions DO NOT OPERATE IN AREAS WITH HEAVY DUST Operating the equipment in high dust conditions will cause deteriation in performance system failure or present a shock or fire hazard Contact the factory for further instructions DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Operating the equipment in the presence of flammable gases or fumes constitutes a definite safety hazard For equipment designed to operate in such environments the proper safety devices must be used such as dry air or inert gas purge intrinsic safe barriers and or explosion proof enclosures DOT NOT USE IN ANY MANNER NOT SPECIFIED OR APPROVED BY THE MANUFACTURER Unapproved use may result in damage to the equipment or pres
29. eform R 0 Ohms ESD standards generally specify total system Capacitance consisting of the fixed capacitor plus the parasitic capacitance For the Model 931 the parasitic capacitance La is approximately 50pF This includes the Capacitance of the HV connectors and internal wiring Figure 3 0 1 is an equivalent circuit of the discharge unit 18 3 1 I pi 100pF Plug in SO CJ ol ed SO OO 200pF 500pF 7 ie TO 0 01uF Hs hae an SPDT Interna limiting HV resistor of 25M RELAY o oo OO oo co e mmm nauctor 0 02uF 770 05uF 70 10uF 2770 25uF 70 50uF from output Pepe Pe I an of HVPS Digital Panel 1000 Meter reads REAR PANEL YQ QQ inductor Figure 3 0 1 Discharge unit equivalent circuit Actual Capacitor and Resistor Values The capacitors used in the Model 931 consist of both capacitor banks made up using series and parallel combinations and custom capacitor modules Each capacitor can be measured by connecting a capacitance meter to the respective capacitor selector round pin However internal wiring and connections add parasitic capacitance to the circuit This capacitance Cp1 is approximately 50pF and must be added to the measured capacitance to obtain the system capacitance Specifications may specify either the capacitor value or the system capacitance System capacitance is the total capacitance that is discharged when the relay closes All capacitors have a tolerance of better than 5
30. el 949 Test Target The discharge will be through the 949 to ground as shown in Figure 5 2 1 CAUTION OBSERVE ALL SAFETY PRECAUTIONS WHEN HANDLING ESD SENSITIVE DEVICES MAKE SURE THE VOLTAGE METER READS LESS THAN 100 VOLTS BEFORE CONNECTING TO THE DUT 28 5 3 Powder Testing CAUTION WHEN TESTING POWDER DO NOT KEEP POWDER SAMPLES NEAR THE FTS WHEN PERFORMING A TEST For testing powders the optional Powder Testing Electrode Assembly is available as a freestanding unit as shown in Figure 5 0 3a or installed in the ETS Firing Test Chamber as shown in Figure 5 0 3b a Free standing unit Firing Test Box installation Figure 5 0 3 Powder Discharge Probe test set up Connect the Red banana plug into the discharge electrode and the Black banana plug into the ground jack as shown in the respective figures Place a powder cup into the ground electrode Adjust the height of the ground electrode to the distance specified from the discharge electrode needle Lock the electrode in place with the lower locking ring Fill the powder cup and place it into the ground electrode then initiate the test If it desired to monitor the discharge waveform two methods can be used The preferred method is to connect the ground side of the test circuit to the input of the ETS Model 949 Test Target The discharge will be through the 949 to ground as shown in Figure 5 1 3 29 6 0 CALIBRATION The Model 931 is calibrated at the factory as follows
31. elector module s with ones containing R or C Capacitor values ranging from 60pF to 0 5uF and resistor values ranging from 0 to 10 000 Ohms are available 1 1 Test Standards Most applications require the determination of the energy threshold required to ignite explosives by electrostatic discharge of varying intensities Resulting data can then be used to characterize the probability of initiation due to electrostatic discharge ESD events MIL STD 1751A Group 1030 Test Methods along with MIL STDs 1576 Method 2205 and MIL STD 331C Appendix F constitute the most common test standards for electrostatic discharge sensitivity testing 1 1 2 MIL STD 1751A This test standard is for testing explosive powders Method 1031 1 Maximum test voltage 5kV 2 Resistor 0 Ohms 3 Capacitors 100 250 500 1000 2000 5000 pf 0 01 0 02 0 05 0 1 0 25 0 50 uf Method 1032 1 Maximum test voltage 25kV 2 Resistor 0 Ohms 3 Capacitors 250pF 0 02 uf 4 Method 1033 1 Maximum test voltage 5kV 2 Resistor 0 Ohms 3 Capacitor 0 02uf other values are implied Method 1034 NATO Std 1 Maximum test voltage 30kV 2 Resistor 0 Ohms 3 Capacitor 0 035uF 34 7nF specified 1 1 2 MIL STD 1576 Method 2205 This test standard is typically used to test devices 1 Maximum test voltage 25kV 2 Resistors 0 5000 Ohms 3 Capacitor 500pF 1 12 MIL STD 331B Notice 3 This test standard is typically used to test devices
32. ent an electrical shock or fire hazard MAINTENANCE and SERVICE CLEANING Keep surfaces clean and free from dust or other contaminants Such contaminants can have an adverse affect on system performance or result in electrical shock or fire To clean use a damp cloth Let dry before use Do not use detergent alcohol or antistatic cleaner as these products may have an adverse affect on system performance SERVICE Do not attempt to repair or service the instrument yourself unless instructed by the factory to do so Opening or removing the covers may expose you to high voltages charged capacitors electric shock and other hazards If service or repair is required contact the factory 1 0 INTRODUCTION The Model 931 Firing Test System is an instrument that is designed to simulate the discharge produced by an electrostatically charged human body when it is brought close to an object that is at a lower potential By use of different R amp C modules the Firing Test System can also simulate the effects of other types of discharges such as a charged conductive object coming in contact with the leads of an explosive device Static charges are generally created when dissimilar objects are brought into contact with each other and then separated When this situation occurs electrons are transferred from one object to the other If these objects are electrostatically conductive e have surface resistance less than 10 Ohms and are both connected to
33. est Chamber with discharge cable Also available is a Powder Electrode Assembly for testing powders that consists of a stainless steel discharge head shown in Figure 2 4 2 with replaceable needle electrodes that is mounted to the top of the unit by a 1 25 32 mm Delrin insulator and an adjustable height sample holder with locking ring that accepts a 0 75 dia 19 mm sample cup Six 6 cups are supplied Additional cups can be ordered 16 2 5 The 3 8 32 tapped hole to hold this unit is plugged with a 3 8 32 bolt when not supplied at time of order Figure 2 4 2 Powder discharge and sample holder assembly A blast shield not shown in photos covers the interlock connector and switch To remove the shield remove the 2 screws securing it to the chamber located on the bottom of the unit NOTE The Firing Test Chamber is not certified to withstand any specific level However the chamber when installed correctly has been found to withstand a firing of a least a 250mg device It is up to the end user to determine whether the chamber will be satisfactory for discharges of their particular device at equal or higher sizes Output Connector Junction Box Optional retrofit If the installation uses another Firing Test Chamber an external Junction Box shown in Figure 2 5 1 is available This Box acts as an interface between the Model 931 Output Cable and device DUT test cables If the DUT cables and or connectors are damaged duri
34. he overcharging the faster the capacitor will charge to the desired level 2 1 1 7 2 TRIGGER This spring loaded toggle switch activates the discharge relay For single shot discharge either the AUTO COUNT switch can be set to 1 or the INTERVAL switch can be set approximately half way and the DISCHARGE switch depressed once For 11 multiple discharges the switch must be held down until the number set is reached The system automatically resets to zero when the switch is released The yellow LED will flash each time a discharge occurs 2 2 1 8 Displays 2 1 1 8 2 1 1 9 2 1 1 8 1 DISCHARGES Display This 0 9 LED numeric display illuminates automatically when the AUTO COUNT FREE RUN mode select switch is in the AUTO COUNT position and is off when it is in the FREE RUN position lt resets to zero when the DISCHARGE switch is in the OFF position up and displays the discharge pulse count when the DISCHARGE switch is depressed When the discharge s automatically stop in the AUTO COUNT mode the DISCHARGES display will indicate the total number of pulses produced for that test sequence The final count will agree with the discharge number set on the SET switch If more than 9 discharges are required then repeat the above sequence Remote TTL Discharge Control Optional When installed an external TTL signal controls a relay that parallels the Discharge switch and will automatically initiate a discharge when a TTL signal is
35. me of order it can be configured to replace the POWER rocker switch Location Place the System on a sturdy table Overall weight including the Firing Test Chamber is approximately 50 pounds 23kg Connect the exhaust port of the Chamber to the appropriate exhaust system The exhaust port is a 2 NPT pipe thread fitting Connect the cables as shown in Figure 4 0 1 for the standard system Figure 4 0 1 Standard System wiring With the Firing Test Chamber connect the system as shown in Figure 4 0 2 22 AN Figure 4 0 2 System wiring with Firing Test Chamber Figure 4 0 3 shows the installation of the optional Junction Box The discharge and ground output connections of the box use standard banana jacks that allow attachment of the cables using either the screw on capability of the jacks or standard 0 162 4mm banana plugs Cable length may vary per customer requirement Figure 4 0 3 Junction Box installation 23 NOTE The replaceable output cable MUST have a rating of 40kV if it is being passed through the wall of a metal firing test chamber OPERATION 5 1 Sample Preparation To perform a test on a device proceed as follows 1 Connect the Output and Ground lead clips to the appropriate DUT Device Under Test pins or leads as shown in Figures 5 1 1a and b Actual connection to the DUT will be determined by the DUT configuration Junction a Box Dischg Input Figure 5 0 1a DUT wiring connections Output
36. mputer or pulse generator Two BNC connectors are located on the rear panel of the Control Unit and require a 3 to 15V pulse For initiating the ARM function the length of the pulse must be compatible with the charging time required for the selected capacitor value To initiate the Discharge function a minimum 1msec pulse is required This Remote function only operates in the FREE RUN mode The number of discharges is controlled by the external triggering The AUTO mode is controlled by an internal timing circuit Capacitors below 0 02uF 20 000pF will charge to the adjusted value in 5 seconds or less However capacitors 0 05uF 50 000pF and above require considerably more than 5 seconds to fully charge to the maximum of 5kV The 0 25uF capacitor requires approximately 90 seconds to charge to 5kV and the O 5uF capacitor requires several minutes to charge However by setting the charging voltage to gt 5kV the exponential charging curve will pass through the 5kV level much sooner By adjusting this over voltage level before hand when the capacitor charge reaches 5kV or other desired voltage the discharge relay can be triggered This is illustrated in Figure 2 0 3 for 5kV but it applies to any charging voltage setting EL ECTRO TECH SYSTEMS INC EXPONENTIAL CHARGING CURVE OF THE 931 FOR 0 5uF CAPACITOR EXACT CHARGING VOLTAGE VS OVER CHARGING VOLTAGE EXACTVOLTAGESET OVER VOLTAGESET TARGET 0 10 20 30 40 50 60
37. ng a test they can easily be replaced 17 Cable length will vary per customer requirement Figure 2 5 1 Junction Box Optional 2 6 Output Probes and Accessories The standard FTS is supplied with the following cables and accessories 1 2 6 T 8 Output Cable 5 1 5m 40kV silicone terminated with HV connector and standard banana plug with replaceable alligator clip Ground Cable 5 1 5m black rubber terminated with standard banana plugs with replaceable alligator clip on one end Control Signal Cable 10 3m 15 pin sub D both ends Additional 10 3m sections can be added to increase cable length up to 40 12m Inter unit Ground Cable 12 3 7m green rubber with standard banana plugs on both ends Custom lengths available Interlock Cable 1 8m 3 conductor PVC signal cable with 3 pin DIN connector on one end and tinned leads on the other end to connect to customer supplied interlock switch A 3 pin DIN connector is installed if the Optional Firing Test Chamber is ordered Custom lengths available Power Cord 8 2 5m IEC to North American 3 prong British 3 prong cable available Capacitor Select Module Resistor modules or resistor select module if resistors are built in 3 0 DISCHARGE CHARACTERISTICS The Model 931 generates discharge pulses that are similar to either the standard ESD Human Body Model HBM exponential waveform R gt 0 Ohms or the Machine Model MM wav
38. ng networks 0 1 0 25 0 5uF turn the voltage up to maximum 5 5kV and when the desired voltage is observed on the meter immediately activate the DISCHARGE switch This will reduce the 0 5uF capacitor charging time to approximately 75 seconds Corresponding reductions apply to the other capacitors There are several ways to initiate a discharge If only a single discharge is desired set the AUTO mode switch to AUTO The LED counter will light Set the COUNTS switch to 1 Arm the system and then depress the DISCHARGE lever switch when the set voltage level is reached A single discharge will occur If more than one discharge is desired then set the COUNTS selector switch to the number of discharges required up to 9 Both the ARM and the DISCHARGE switches must be depressed during the entire CHARGE DISCHARGE cycle s If more than 9 discharges are desired the sequence must be repeated The discharge cycle can be ended at any time by just releasing the DISCHARGE switch If the AUTO mode switch is set to FREE RUN then the system will continue to discharge at the rate set by the INTERVAL control until the DISCHARGE switch is released If the control is set high enough single discharges can be obtained in this manner also In either case the operator always controls the ARM and DISCHARGE functions If the optional TTL Charge ARM Discharge trigger circuit is installed select the FREE RUN mode This cycle will then be controlled automati
39. ors The lockout is controlled by the plunger installed onto the CAPACITOR SELECT module that activates individual switches incorporated into the Discharge unit to allow only capacitors up to 0 02uF to be charged up to 26kV HIGH VOLTAGE ADJUST Control This 10 turn rotary control is used to set the level of the high voltage supply to the desired charging voltage The magnitude and polarity of the charging voltage are indicated by the Ac digit CHARGING VOLTAGE meter The HIGH VOLTAGE ADJUST control is set prior to initiating a discharge sequence This control is nonlinear where it will require more turns to adjust the low end than it takes to adjust the high end The charging voltage level increases as this control is rotated in the clockwise direction INTERVAL ADJUST This rotary control allows the operator to set the time interval between discharge pulses This interval is adjustable from a minimum of 1 3 second to over 10 seconds Rotating the control clockwise increases the time interval between discharge pulses NOTE The charging circuit incorporates a 25 megOhm series resistor As the value of the capacitor increases the charging time also increases by t 5RongC This determines the minimum interval that can be used For capacitors lt 0 02uF the charging time is lt 5 seconds Therefore the Auto Count mode can only be used with capacitors up to this value 10 For larger capacitors charge time becomes very long Therefore
40. ring test are not covered under warranty Replacement parts are the responsibility of the user ETS can supply replacement parts as ordered Several spare clips are included with the unit Additional clips can be ordered from ETS or obtained from a local electronics parts distributor or store Spare Parts The Model 931 is a custom made system that utilizes a number of components that are specifically made per ETS specifications The following Table lists both ETS and component manufacture name and part number for those items that may have to be replaced by the user Components exclusive to ETS are listed with ETS Part Numbers Standard parts are listed with manufacturer and their respective part number In some cases such as IC transistors diodes switches etc similar parts from other manufactures can be substituted if necessary 39 Spare Parts List a BS JAP O CA Con Unit 2 Point source LED LO Grn 0050 00007 Bivar_______ PM3GDW6 A Red 0050 00006 PM3HD W6 Pp 4 CHARGE Red 0050 00003 PM5HD W6 DISCHARGE Yel 0050 00002 PM5GD W6 7 INTERVAL ADJ Pot 0066 Honeywell 308N1MEG AJOIN 0001M 10 11 12 14 15 16 17 18 12 3 7m Interconnect Cable ___ OpenStock DB15M DB15F 19 20 AR as S S 22 Group Bd o o G y o IC 8 PIN LM555 0090 00016 Fairchild Semicond LM555CN EA CA3140 0090 00018 CA3140AEZ A LM741 0090 00007 STM Micro Elect UA741IN AUS E
41. ronments and products are present It is virtually impossible to control the environment in which most of today s high technology equipment or explosive products are used The burden falls on the manufacturer to design and build equipment devices and formulations that can function without disruption or failure when subjected to commonly occurring electrostatic discharges The Model 931 Firing Test System can be an invaluable aid in helping to determine the minimum energy levels required to damage equipment or ignite a particular compound or device The Model 931 Firing Test System can produce discharge pulses from lt 100 volts to gt 26kV Energy is stored in capacitor banks during the charging cycle A discharge pulse is produced when a high voltage gas filled relay disconnects the charged capacitor bank from its charging source and reconnects it to the output of the FTS Discharge Unit The energy storage capacitor bank is installed inside the Discharge Unit The discharge resistors are either installed within the Discharge Unit or are contained in individual plug in modules Capacitor and resistor values are selected by the user and the initial configuration must be ordered at the time of purchase Additional standard and custom capacitor and resistor modules are available These can be plugged into either an optional SPARE capacitor input connector combining several internal capacitors using multiple plug in selector modules or replacing the S
42. rst 50 nsec is within 10 of the calculated peak current value for resistances greater than 250 Ohms At low capacitance and resistance the overall impedance of the circuit begins to dominate the peak current measured The waveform using 0 Ohms is a damped oscillation where the peak current is determined by the impedance of the circuit rather than primarily the resistance Typical waveforms for the following R C combinations at 5kV are shown in Figure 6 0 4 and for 25kV in Figure 6 0 5 100pf amp 0 5kV only 500 1500 amp 5000 Ohms 500pf 8 0 5kV only 500 1500 amp 5000 Ohms 2000pf amp 0 5kV only 500 1500 amp 5000 Ohms 33 Tek Run 16575 Sample IEE Tek Run 1605 5 Sample DER e LE Lu e LE LA wa sv A Stns tht FTV CH RECKEN As Chi 1 92V 30 Sep 2005 30 Sep 2005 14 13 18 14 16 01 R 00 R 5000 Tek Run 200MS s Sample IEE e F dE 3 Oct 2005 08 54 28 R 50000 Discharge waveform 5kV C 100pF Tek Run 200MS s Sample IEE di ech ee E ja Se me EE F Go gt E Tek Run 200MS s sample g A A i i i ao PA EF peo za be hl ov M250ns Chi Y TV a 2 oo sins Caty 1 92V 30 Sep 2005 30 Sep 2005 14 36 59 14 40 16 R 00 R 5000 34 Tek Run 100MS s Sample IER e TF GE V 3 Oct 2005 09 03 49 R 50000 Discharge waveform 5kV C 500pF TER Gums e ee Se denen Tek Run 10MS s Sample IEEE r O oe EE F Ee GE a D 5 Y M250ns Chl y 30 Sep 2005 15 00 24 3 O
43. s The lower the humidity the longer it will take a charged nonconductive object to dissipate the charge A person walking across a carpet or tile floor on a dry day is capable of generating an electrostatic body charge in excess of 15 000 Volts When the person comes in contact with a conductive object he immediately discharges the accumulated charge on his body If the charge build up is about 3 000 Volts the person will feel only a slight shock However if the charge build up is much larger a visible spark discharge will occur that can cause not only discomfort to the person but with enough energy an inadvertent ignition of an explosive product or device In the past electrostatic discharges were generally of less concern than they are today With the introduction of more and more synthetic materials many of which are easily charged and the development of complex electronic equipment that may contain electrostatic discharge sensitive components plus the use of explosive initiators in consumer items such as automotive airbags and seatbelt pretensioners the effects of electrostatic discharge have become a major concern Many electronic components can be damaged or destroyed when subjected to electrostatic discharges of less than 100 Volts Discharges of thousands of volts can have 3 devastating effects on electronic communication systems medical electronics computers home entertainment systems locations or products where explosive envi
44. sh the ARM spring loaded lever switch DOWN and hold it there throughout the charge discharge cycle This will activate the HV power supply A voltage level will be displayed on the 4 digit LED display Rotate the VOLTAGE ADJUST knob large diameter knob until the desired voltage level is reached This is a 10 turn potentiometer where voltage changes more rapidly as voltage is increased If the TTL Charge ARM Discharge option is installed the voltage must first be adjusted as described above 26 NOTE The charge time is exponential and is a function of the internal current limiting resistor and the capacitor selected RC time constant To reach approximately 99 of full charge can take at least 5 time constants t 5RC plus other limitations in the charging circuit The larger the capacitance the longer the charging time required For large value capacitors the charge time can take as long as several minutes 0 5uF to reach the exact voltage setting for example 5 00kV Therefore to quickly set the voltage for capacitors gt 0 1uf select the 0 01uf capacitor to set the voltage level to avoid the long charging time associated with the 0 1 0 25 and 0 5uf capacitors then switch back to the desired capacitor value To initiate a discharge push the ARM switch DOWN and when the CHARGING VOLTAGE meter displays the full voltage selected depress the spring loaded DISCHARGE lever switch To reduce the testing time for the slow chargi
45. t Box configured for device testing this capacitance is approximately 25pF Longer cable lengths and other discharge electrode configurations will increase the capacitance The residual charge will bleed off at the rate of t 5RC 125msec for the FTB configuration If the capacitance of the device under test DUT is high then the bleed off time will be longer The rate at which the residual charge on the capacitor bleeds off is a function of its value and the resistance in the charging circuit The voltage remaining on the capacitor after a discharge cycle has been initiated is indicated by the meter reading Even though the voltage on the capacitor is isolated from the output by the relay it is recommended that the DUT not be handled until the Charging Voltage meter reads below 100 V The 35kV gas filled SPDT high voltage relay is used to perform all charge discharge functions It is used in place of the approaching electrode charge discharge configurations referred to in some specifications The front panel consists of the Polarity Reversing Module and two or more 2 pin high voltage selectors that enable the user to insert and or select combinations of capacitor and resistor networks Those R C networks that are installed internally must be specified at time of order 14 When additional capacitor values below 500pF are specified they can be incorporated into individual plug in modules Refer to Figure 2 2 1 When no resistor or c
46. us the bleed off cable to discharge the capacitors ets electno d EE STE DISsCiAECE U WD A a SER RO on ibi ie mara TEST Sr MODEL au Figure 2 2 3 Discharge Unit Rear Panel 15 2 3 Custom Configurations Custom Discharge Unit configurations that are installed at the time of order such as selection of multi pin device selectors and separate discharge units or retrofitted devices are described and added in the Appendix along with special instructions 2 4 Firing Test Chamber Optional An optional Firing Test Chamber FTC shown in Figure 2 4 1 measuring 16 75 Wx9 Hx12 D 42 6x23x30 5cm is fabricated from 0 375 9mm cold rolled steel continuously welded along all seams is available A 0 375 9mm steel door with a Y 6 mm rubber seal is firmly locked in place with a heavy duty toggle latch The door activates a recessed vandal proof stainless steel interlock switch that turns off the HVPS when it is open A door with a 0 75 18mm acrylic or polycarbonate window is also available The rear of the unit has a 2 NPT threaded fitting for connecting an exhaust Also on the rear are the interlock HV discharge and ground connections When ordered the ETS Model 949 Test Target is also installed Supplied with the Firing Test Chamber is a 2 pin High Voltage connector with 12 output and ground lead cable with standard banana plugs and replaceable alligator clips Figure 2 4 1 Firing T
47. y inserting the white silicone wire into ALL capacitor selector inputs Residual charge on the capacitor will damage the capacitance meter or result in the operator receiving a shock With large capacitance this can result in serious injury Residual charge can remain for long periods of time Resistance The resistance is measured using a resistance meter with an accuracy of at least 1 1 Resistor Selection System A The resistance of the internal resistors can be measured by inserting one meter probe into the round side of the desired Resistor Select connector on the front panel and the other probe into the round side of the O Ohm Select connector All resistors are connected together at the Output connector on the rear panel The 0 Ohm resistor is a direct connection from the Output connector to the 0 Ohm Select connector 31 2 Resistor Module System D The resistance of the Resistor module can easily be measured by inserting the meter probes into the module connector and taking a measurement 6 3 Discharge Waveform 1 The discharge pulse is measured using an ETS Model 949 IEC Test Target and an Agilent Model DSO 6102A oscilloscope having a single shot bandwidth of 1 GHz and a sampling rate of 4 Gigasamples sec The connection to an external Test Target is shown in Figure 6 0 3a and to an unit installed in the Firing Test Box in Figure 6 0 3b The Test Target if ordered comes complete with 20db 2W Attenuator r
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