Original DTMF-16 Book
Contents
1. v9n angy Pal lt 2 1088 gosg sn EN oos H rH i 2 E 5 Lot dai ud 4 Sg urs 264 53 Ag peissisp suo zT er vb 4 j t Burpunsug AOL bz E Coors zea 9 i 91 NS su ST T T aL ven 4 gt ir rise d u sis 15 Lat H tis MOL 4 t i 6H OBA 26M 2 L ts aen EL TT 7 oz OLS 1 8 ZT ET A ovn E58 mr 208 185 eT 17 18 in FT ry er Eo 2 T en ts Pegs av ST z1 o1 55 Ei 21 E A sH is amp 3 Y ST T 6 05 ta IR ta NI ven en 1H A Ix ax Xx Hp TH T zHWAe4s Sen 1 bz 8 WOL 2 aen 4 zu 95 i FT TH ST bl i oT T ven LlLawLa Typical Output Hookups 1992 CircuitWerkes All Rights Reserved CircuitWerkes _ Title OUTCON3 i ge Document Number Pyare Po Rev Date 10 08 92 Thu Sheet Rev Bu Typical DTMF 16 output wiring Specific examples for interfacing the DTMF 16 to relays and TTL CMOS inputs can be found on page 8 4902. 12vdc unreg is on pin 22 of the db37 connector Gnd is pin 21 Optionally you can power the relay s externally NOTES CircuitWerkes Title Always use a reverse biased de glitching DTMF16 SAMPLE RELAY DRIVER diode on the coil of the relay s Size Document Number REV Maximum sink current for the standard Darlington output is 150mA Sample hookup of 1 output to pull logic input low User s equipment Pullup Resistor Cinternal to device I 1 1 I 1 1 I 37 TIL or CMOS in 1 I 19 1 Emitter T dL 1 r Never exceed 30 volts emitter to collector Some low current TTL or CMOS inputs may require use of non Darlington open collector outputs Non Darlington output chips are available from the factory at no cost iSize lDocument Number IREV Appendix A Simple Tone Detection Delay Anti Falsing Filter that YoucanBuild to Interface withtheDTMF 16 Description In applications where the DTMF 16 decoder is used in the presence of random voice audio occasional music or speech passages may contain frequency combinations that cause the decoder to activate In almost every case the offending passage lasts for less than 1 10 of a second The anti falsing filter works by slowing down the DTMF decoder s ability to detect the tones Since a decoder using the filter can only see tones longer than the timi
3. act together as a non inverting buffer insuring that input signals to the timing section of the filter circuit are clean and predictable Each time a DTMF tone is detected the DTMF 16 s internal DV transistor pulls the input of Ula low causing it s output to go high Uld s input is tied to Ula s output so that it inverts the high output back to the original low output of the DV transistor and sinking Ulb s input via time constants R2 amp U1 is configured as an inverter and holds the DTMF 16 in a disabled state when no tones are present When capacitor is discharged to about 1 2 U1b changes states The time that it takes to discharge is the detection delay Decreasing the value of R1 will allow C1 to discharge more rapidly shortening the detection delay The output of U1b is fed to the En input which is held low until the time constant expires enabling the DTMF 16 When tones are detected U1d s output is high and charges back up to via U1 s unused gate input is tied to ground to prevent destructive oscillation Connections inside dashed line l are made to the 2 by 4 pin headers on the DTMF 16 board Yee G En 8 DV are the row closest to the board s edge 1 Use Molex pins or IDC connector 1 4093 Tor header connectors Be aure that no wires touch each other 1 1 4093 power pin iz 14 4093 ground is pin 7 CircuitWerkas Note Ri s value determines delay timing In
4. pulls up the Follow pin pin 1 on the 4514 and turns on transistors q3 and q4 during the DV pulse When q3 is thus energized it pulls the INHibit pin pin 23 of the 4514 low enabling the chip to place a high on the output selected by the SSI202 s hex coded BCD data Meanwhile q4 turns on and then back off with the DV pulse q4 s high going trailing edge triggers the DTMF acknowledge beep circuit The 4093 s pin 10 u6c goes high for a short period of time determined by c9 and r12 after q4 s high going edge occurs Uld inverts ulc s pulse and gates the oscillator formed by ula ulb c8 r10 and r11 for the duration of the pulse The resluting short burst of mdirange square waves is cap coupled to the audio input so that any valid DTMF tones 1s followed by a brief acknowledge beep If the DTMF 16 is not being used in a situation where a confirmation that the DTMF tone was decoded is desired jumper J2 can be pulled to disable the beep When the decoder is set via jumper 1 to interlocked latching mode the INHibit pin of the 4514 is always held low keeping the last selected output activated until a new DV pulse accompanied by new BCD data occurs The 4514 directly drives the 16 darlington optocouplers to saturation The Optocouplers are quad packaged for higher density board designs An onboard 5 volt regu lated supply easily handles the circuit s power needs Problem Solution Problem Cause Problem Cause Problem So
5. 3 49qunN iusunooQ ezrs a BurarM L AWLA 9I3Tl S9 49M31n2412 siubiy 48A1In240j 661 e nnnnnnn CO ooo pueog 4spoosQ FL AWLA uo Jzegd 61 26 EIN oe 21 sk re Sly vie Ele ck os bh 62 Ol 22 4 sz ES ve amp 24 z OL om lt 2 uouuoo xeu 2PATL B uun xou pub 2949435 MOT 493991199 BurarM 9L 4WLA So xJeMirnoaura nnnnnnn Sample hookup of slave relay on 1 output The relay will operate whenever the output is active This example is wired to operate with the 1 output K1 External relay 3 29 4 7 6 8 58 o gt pin 22 on db37 or external V for relay le 1 Se D1 1N4004 37 19 pin 21 on db37 or external supply ground 12 volts at up to 100mA is available for relay power
6. For Original DTMF 16 circa 1992 93 without Jumpers J3 amp J4 CircuitWerkes DTMF 16 Installation amp Service Manual Description The CircuitWerkes DTMF 16is an integrated Touch Tone detector and sixteen output decoder offering an optoisolated Darlington output foreach ofthe sixteen standard DTMF tones Seperate emitters and collectors are available for each of the twelve common DTMF tones 1 9 0 and Seperate emitters andacommon collector are brought out for DTMF Tones A B C and D The open collector Darlington outputs provide 5000 volts of isolation andare capable of sinking up to 150mA continuously emitter collector voltage should notexceed 30 volts These outputs along with 12 volts DC unregulated and various internal test and interface signals are available at the unit s D SUB 37 pin connector Installation amp Operation Setup The DTMF 16 comes from the factory ready to use just hook up an audio source to the tip and ring the sleeve is left floating on the DTMF 16 s 1 4 audioinputjack connect your equipment to the supplied DB37 male connector plug in the power supply and it s ready Typical hookup diagrams are supplied in the schematics section at the end of this manual There are six jumpers on 16 board all except for the mode jumper amp beep acknowledge set CLOSED from the factory The Mode jumper when OPEN selects momentary decoder operation The momentary output is activated only
7. ble to provide at least 150ma The DTMF 16 s audio connection is made via the 1 4 inch jack located next to the power connector The connector is a tip ring amp sleeve type with the tip amp ring making the audio path The audio input is an unbalanced input with an input impedance of approximately 10kOhms Input impedance of the DTMF 16 is 600 Ohms when it is packaged with and connected to the AC 2 autocoupler Audio input level must be between 0 5 and 10 volts peak to peak Care amp Feeding Generally the DTMF 16 may be placed anywhere other electrical equipmentis in operation As always itis best to avoid extreme temperatures immersion or high impacts If you wish to clean the outside of the DTMF 16 use adamp cloth soaked in a mild soap and water solution Detergents alcohol or solvents may remove the screen printing or mar the case Theory of operation Input audio is capacitor coupled to the Silicon Systems SSI202 low power DTMF receiver The SSI202 requires only one resistor and one crystal for frequency reference The hexadecimal coded output is decoded by the CMOS 4514 4 to 16 line decoder The hex coded BCD data is connected directly to the 4514 decoder but the data valid strobe pulse from the SSSI202 drives the bases of two npn switching transistors q1 and q2 q2 s sole purpose in life is to be an inverter buffer of the DV pulse for the accessory header 2x4 pin header located beside the 4514 chip q1 more importantly
8. corresponding D Sub pins 7 and 25 can be used by other assemblies in the product enclosure like the optional ComboLok see OPTIONS J 5 and J 6 connect the C and D emitter outputs to D sub pins 24 and 6 respectively Also can be used as described for J3 and J4 sesx4eMinisdr2 L 1 Jequeseg Jequnn 2 deposed 91 etal ay SR 00 PEZ EN 1 surd 107 29 Atddng I EN amp tddns demod euo ey uoryeunp INI SY z ansa OL ru sesseuour Burssedour deeq eBpe MGuxaS ey ey oes oec eutuJeisb 62 9 218 Siueusduoj APER PT 5 7 L E zT tH 1 giu ceo TT 1 aee sr L sen an ET Ed it AUT T gt 71 65 vzn u or L sen oT tl T gr En gt 4 er
9. creasing R1 increases ane Gainesville Florida 32607 Tor DTMF 15 to react to tones decoder Talses increase 204 222 222 If it 1 9176 up dd Tones decrease 33k provides Title approximately secon elay er typical values w a between 15k and DTMF 16 Hash Filter Delay ppc eee 1 Date n 2g hes a Note about parts substitutions U1 is a 4093 Schmitt triggered quad NAND gate which provides clean output switching in the presence of a slowly changing input Although this circuit design was tested and found to work using the more common 4011 NAND gate it is not guaranteed to function correctly in every case where a 4011 is substituted 9 REPAIR OR SERVICE INFORMATION In the event of the need for service or repair call Circuit Werkes at 352 335 6555 for a Return Merchan dise Authorization number RMA Thencarefully package the unit along with a note of the problem and senditto the address below Clearly indicate the RMA number on the outside of the box We cannot acceptreturns without an RMA Be sure to include your address nota PO box telephone number and besttimeto call CircuitWerkes ATTN CUSTOMER SERVICE DEPT 2805 NW 6TH STREET GAINESVILLE FL 32609 CircuitWerkes Limited Warranty This product is warranted against defects for two years from date of purchase from CircuitWerkes and CircuitWerkes authorized distributors Within this period
10. for the duration of the incoming tone When the mode jumper is closed the decoder is in interlocked latching mode When in latching mode the selected output remains activated until another outputis selected The second internal jumper near the 4093 chip enables the acknowledge beep when installed The beep jumper is normally shipped in the open mode when the DTMEF 16 operates by itself The jumper is normally set in the closed position when the DTMF 16 is part of acombined autocoupler circuit such as the AD 16 The remaining fourjumpers labelled A D are simply in the paths of the A D outputs of the decoder they are normally installed in the closed position at the factory In the closed position outputs A through D appear on the D 37F output connector If needed the jumpers can be removed and the corresponding four pins of the D 37F output connector can be accessed for other purposes For example special ComboLok options can be interfaced to the outside via these pins Basic Operation The DTMF 16requires no operator intervention It monitors an audio source until a valid tone occurs then energizes the tone s corresponding Darlington output optocoupler The resulting open collector output appears on the unit s db37 connector Connections The power connection is made via 2 1 mm coaxial jack and will accept from 8 to 18 Vac A power supply is provided with each DTMF 16 however if you wish to supply your own it must be a
11. lution Problem Cause Trouble Shooting DTMF 16 outputs test good but won t activate my equipment Polarities on a logic input may be reversed In some computer related cases a different version of the DTMF 16 output chip may be required replacements are available free from the factory Adding an external relay can also solve this problem One ormore outputs do not operate with an incoming tone Beep works Failed optocoupler s failed 4514 or low and or noisy input None of the outputs function with incoming tones BCD data during incoming tone good at pins 1 18 17 16 of the SSI202 Incorrectly wired output connector bad 4514 bad q1 q3 or r3 r4 open No outputs function and there is no BCD data on pins 1 18 17 or 16 of the SSI202 Power supply failure check bridge first improper audio input bad SSI202 or damaged crystal No beep Outputs functioning properly on db37 4093 failedor ack jumperremoved Note Excessive current through the emitter collector junction of the optocouplers will destroy them Options The DTMF 16can be packaged with the AC 2 autocoupler to provide a fully integrated 16 output remote control Also available is the CircuitWerkes digital combination lock a four digit sequential combination lock with over ten thousand possible combinations The combination lock will enable the DTMF 16 only after the correct sequence of numbers is entered If also used with an AC 2 the combolok can fo
12. ng window spurious tones are rejected The anti falsing filter is designed to connect to the DTMF 16 decoder board s 2 by 4 I O connector and provides additional immunity to spurious audio transients while still reliably detecting DTMF tones The circuit shown is simplified in order to be easily built A deluxe version of this circuit that includes a tone activated audio mute is available as a field installable board for a nominal charge from your CircuitWerkes dealer Connections Four connections are required to interface the filter to the DTMF decoder All four of these connections should be made on the 2 by 4 pin header located between C7 and R9 at the back of the board The four connections Ground Enable input amp Data Valid strobe output These four pins are located in a row closest to the edge of the board Note that the four pins that make up the inside row closest to Q3 are labeled A through D No connection should be made to these pins An Insulation Displacement Connector IDC or Molex type pin connectors should be used to make connections to the DTMF board Care should be taken so that no wires touch each other particularly Vcc and anything else Since both ground and ground sinks are present on some pins accidentally touching them to Vcc may have very unpleasant and destructive results for both the DTMF 16 and the filter How doesit work Theory of Operation Ul isa 4093 quad NAND gate Ula amp Uld are designed to
13. rce the coupler to hang up ona caller that does not enter the correct security combination within a short time window Contact your CircuitWerkes Dealer for more information on Circuit Werkes products DTMF 16 Layout Diagram a3 1 In a3 AC or DC 2 n Rif 551202 o 10M oo j 8 Collector In pen Co Out for val Id u Rz o 8 pin DTMF Tones e lol o 0 an2222 O NEC2S02 2 On Latching see text Off Momentary CO C 1 wh i 00000000 00000000 00000000 OW mfoooQ Hedre oloco 8808 Acknowledge beep On Enable acknowledge tone Off Disable acknowledge tone 502 4 37 pin D sub 35 output connector o 5 1k 00000000 ARAB 1666006600600 606 606066625 J J A b can be removed disabling the A and B outputs so that the
14. we will repair it without charge for parts and labor Proof of purchase date required Warranty doesnot cover transportation costs or a product subjected to misuse accidental damage alteration except as authorized by CircuitWerkes improper installation or consequential damages Except as provided herein CircuitWerkes makes no warranties express or implied including warranties of merchantability and fitness for a particular purpose Some states do not permit limitation or exclusion of implied warranties therefore the aforesaid limitation s or exclusion s may not apply to the purchaser This warranty gives you specific legal rights and you may also have other rights which vary from state to state 10
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