ATT-20 Audio Track Transceiver
Contents
1. HARDWARE SHUNT USED DURING SET UP O 1 3 5 5 5 7 4 502 p Los 80 34 ATT 20 Ky TWISTED PAIR 8 Figure 2 1 Shunt Mode Track Circuit Application SM 6299 Rev 1 0 June 2008 2 1 Application Installation and Adjustments SN 77 AnsaldoSTS Union Switch amp Signal 2 3 Series Mode Track Circuit Application In this application the transmitter and receiver are wired in sequence via a jumper on the ATT 20 unit This jumper connects transmitter output terminal 4 to the receiver input terminal 6 The remaining transmitter output lead terminal 3 and the remaining receiver lead terminal 5 are twisted as a pair and each is connected to its respective rail see Figure 2 2 The presence of a train axle across the rails completes the series signal path thus detecting the approach of a train The series mode of operation is a non vital application 12V BATTERY 383 0003 00 2 2 OHM SHUNT 75 gt 60 FEET ADJUSTMENT SHUNT mina ME CABLE COMPENSATING TWISTED PAIR Figure 2 2 Series Mode Track Circuit Application SM 6299 Rev 1 0 June 2008 lt 7 AnsaldoSTS T l Union Switch amp Signal Application Installation and Adjustments 2 4 Terminal Connections AAR type terminals are located on the top of t2. 1 2 1 3 3 gt Receiver Characteristics tk Societe oed 1 2 123 4 MiSCella eguSu uuu iet ER Re t dtd edt ae 1 3 2 APPLICATION INSTALLATION AND ADJUSTMENTS 2 1 21 2 u ou ea eee uuu n e fedes Qu au qa OEE a lel 2 1 2 2 Shunt Mode Track Circuit Application nana 2 1 2 3 Series Mode Track Circuit Application nennen 2 2 24 Terminal oeste os Pme ees entend 2 3 2 5 Mounting enne ener nennen nennen nnne 2 3 26 General Considerations i doe HG test al einai nid Arnie 2 3 27 Sh nt Mode Operation ciiin ase eee T acce cii o end ope 2 4 2 7 1 Shunt Mode Installation 2 4 2 7 2 Shunt Mode eed eene 2 5 2 8 Series Mode Operation snnt esten nns 2 6 2 8 1 Series Mode Installation L a D A AN Sa ASA u nM a Saa s 2 6 2 8 2 Series Mode Adjustment without Cable Compensating 2 6 2 8 3 Series Mode Adjustment with Cable Compensating 2 7 2 9 Lighting Protection sie su tdt p e tinet ep ele v
3. CO Figure 6 1 ATT 20 Wiring Diagram SM 6299 Rev 1 0 June 2008 6 3 A 77 AnsaldoSTS Parts Lists Union Switch amp Signal SIDE TL6 TL5 BATTERY XMT RCV RELAY B s LOWER O RAISE RELAY VOLTS AUDIO TRACK SHUNT TRANSCEIVER TL1 MODE MODEL ATT 20 UNIT FREQ REV j TL4 TL2 O AJ C SWITCH WN amp SIGNAL INC PITTSBURGH PA 15237 o lt Figure 6 2 20 Parts Illustration g lt 6 4 SM 6299 Rev 1 0 June 2008 5 77 AnsaldoSTS Union Switch amp Signal Parts Lists 6 4 Cable Compensating PCB Parts List Refer to Table 6 6 and Figure 6 3 for Cable Compensating PCB US amp S N13100201 parts parts layout and schematic diagram Table 6 6 Cable Compensating PCB Parts List Item Part No Description Quantity 5 NS381621 BLOCK TERM 1EA 10 N13100101 PCB CABLE COMPEN 1 EA 15 J047818 WASHER 17 64X9 16 COP 2 20 5000970128 SCR SST 1 4 20 1 3 4 2 EA 25 44751200112 WASHER SST PLATE 1 4 2 EA 30 J4751210111 WASHER SST LOCK 1 4 2EA 35 J4802110108 1 4 20 SST HEX 2 EA 22uFD z E T e a o o
4. 65 J047714 WASHER 8 SHPRF LK SS 4 70 J048166 NUT 8 32 HEX STEEL 4EA 75 M337854 INS TUBING 8 EA 80 J052686 SCREW 8X3 8 RD HD 4 85 J730041 TERM PRE INSUL DIAGR 8 EA 90 J078399 BAG PLASTIC 60F 0406 1EA 100 S705 11 WIRE TAG 12 BUNDLE 1EA 105 J075415 GROMMET RUBBER 3 8 ID 1EA 110 A774169 TUBING HT SHRINK 3 16lD 115 A774184 TUBING SHRINK FIT 1 16 120 A434083 1 TW PR SHELDD MIN 6 FT 125 J703310 CABLE TIE SELF LOCKING 5EA 6 2 SM 6299 Rev 1 0 June 2008 5 77 AnsaldoSTS Union Switch amp Signal Parts Lists Table 6 5 20 Part Tabulation H CHASSIS XMITER PCB RCVR PCB ATT 20 Unit Freq KHz Application Item 5 Item 15 Item 20 N451052 3901 12 28 Shunt R451053 6302 N451605 6402 N451605 6502 N451052 3902 15 Shunt R451053 6302 N451605 6403 N451605 6503 N451052 3903 20 Shunt R451053 6302 N451605 6404 N451605 6504 N451052 394 12 28 Series R451053 6303 N451605 6405 N451605 6505 N451052 3951 15 Series R451053 6303 N451605 6406 N451605 6506 N451052 3961 20 Series R451053 6303 451605 6407 N451605 6507 03 50 70 TL1 B O R ORELAY TL6 B TL3 B O JE I ORELAY TL5 TL6 TRACK R TRACK TL TL5 TRACK TL2 SHIELD E SHIELD POWER 59 A POWER B GND O I TL2 n TL4 O GND SHIELD N RCVR PCB
5. m a o ISS A Figure 6 3 Cable Compensating PCB Parts Layout and Schematic Diagram SM 6299 Rev 1 0 June 2008 6 5 ay 77 AnsaldoSTS Parts Lists Union Switch amp Signal AM 77 AnsaldoSTS Union Switch amp Signal 6 6 SM 6299 Rev 1 0 June 2008 lt 7 AnsaldoSTS RAIL Team and Technical Support Union Switch amp Signal 7 RAIL TEAM AND TECHNICAL SUPPORT The Rapid Action Information Link Team RAIL Team is a group of experienced product and application engineers ready to assist you to resolve any technical issues concerning this product Contact the RAIL Team in the United States at 1 800 652 7276 or by e mail at railteam switch com SM 6299 Rev 1 0 June 2008 7 1 A 77 AnsaldoSTS RAIL Team and Technical Support Union Switch amp Signal 5 77 AnsaldoSTS Union Switch amp Signal End of Manual 7 2 SM 6299 Rev 1 0 June 2008
6. Lightning Arrester and Surge Ripple Filter for Series Mode Application SM 62989 Rev 1 0 June 2008 2 9 N 77 AnsaldoSTS Application Installation and Adjustments Union Switch amp Signal m 77 AnsaldoSTS Union Switch amp Signal 2 10 SM 6299 Rev 1 0 June 2008 ay 77 AnsaldoSTS Union Switch amp Signal Functional Description 3 FUNCTIONAL DESCRIPTION 3 1 General The transmitter produces an output signal in the high audio frequency range and is sine wave modulated to provide noise immunity First the receiver detects the modulation information signal It then amplifies and rectifies this signal to provide a DC output which drives the relay coil Functional description of the ATT 20 applied to the shunt track circuit is covered in Section 3 2 Section 3 3 covers the series mode track circuit 3 2 Shunt Mode Track Circuit As illustrated in Figure 2 1 the transmitter output and receiver input are cabled directly to the rails The point at which the transmitter wires are connected defines one end of the track circuit The other end of the track circuit is defined by the receiver connections to the track The receiver detects the presence of a train by the loss of the audio frequency signal which is shunted away by the train axle The shunt mode of operation is defined as a vital application 3 3 Series Mode Track Circuit As illustrated in Figure 2 2 the transmitter and receiver are wired in series via a jumpe
7. T T o TL1 TL4 DES 0 k Y SM 6299 Rev 1 0 June 2008 Figure 1 1 ATT 20 Dimensions 1 3 AS 77 AnsaldoSTS General Information Union Switch amp Signal 5 77 AnsaldoSTS Union Switch amp Signal 1 4 SM 6299 Rev 1 0 June 2008 5 77 AnsaldoSTS Union Switch amp Signal Application Installation and Adjustments 2 APPLICATION INSTALLATION AND ADJUSTMENTS 2 1 General This section provides information on the application of the ATT 20 as well as installation and adjustment procedures for the ATT 20 and related equipment It is also critical that this section be read in its entirety prior to any application considerations 2 2 Shunt Mode Track Circuit Application In this application the transmitter output and receiver input are connected by cable directly to the rails The connection is made through surge protectors by twisted line pairs as shown in Figure 2 The point at which the transmitter wires are connected defines one end of the track circuit While the other end of the track circuit is defined by the receiver connections to the track The receiver detects the presence of a train by the loss of the audio frequency signal that is shunted away by the train axle The shunt mode of operation is defined as a vital application 300 FEET RING BY MAX USSP 21 USSP 21
8. Y 1N914 E R13 R16 T 33K 10K R22 3 6M lcs R23 iO R12 470K 2N3117 D3 1N914 lt 5 85 TL4 a n Figure 3 1 Transmitt6er PCB Schematic Diagram SM 6299 Rev 1 0 June 2008 77 AnsaldoSTS Functional Description Union Switch amp Signal 3B3 0009 00 POWER Oc cio RH 47uf 1 1 TP2 47K Sisuz TRACI 94 2N3117 R6 c4 Di C8 R10 AW i 4 i WW 5 TBD TAB TAB 1N4936 02uf 1K R7 cn 04 OA O 10uf 1N4003 1N4003 RS ps pe 13814 100 TABBLS 148 C57 psg 200K R12 Ri6 03 Cu TAB z 10K z 100 14003 Tout TL2 L2 D10 TRACI 909 44 OB LVA462 R4 10K G15 R22 R17 10K Q axo OG1r Oc 1 8K R23 300 Aig R24 240K Q6 20K 2N3117 Q7 36 2N3117 LVA450 f 2ND R26 g Q10 2k 2N2270 TPS i i ns i c17 L6 BO m 599 RELAY BO GND 6 8uf Dii 4037 1 5KE16CA TL6 R27 Ree 17 680 38 qon RELAY Figure 3 2 Receiver PCB Schematic Diagram SM 6299 Rev 1 0 June 2008 ay 77 AnsaldoSTS Union Switch amp Signal Field Maintenance 4 FIELD MAINTENANCE 4 1 General The following procedures may be used to check the ATT 20 at its field installation These pr
9. amp Signal A 77 AnsaldoSTS Union Switch amp Signal 4 4 SM 6299 Rev 1 0 June 2008 7 AnsaldoSTS Shop Maintenance Union Switch amp Signal 5 SHOP MAINTENANCE US amp S recommends that faulty ATT 20 units be returned to the factory for shop level testing and repair Both the transmitter and receiver PCB s must undergo special testing calibration and component replacement per frequency procedures If board level maintenance is to be attempted contact US amp S Engineering for special instructions Appendix A provides a complete listing of all transmitter and receiver PCB components SM 62989 Rev 1 0 June 2008 5 1 AS 77 AnsaldoSTS Shop Maintenance Union Switch amp Signal 5 77 AnsaldoSTS Union Switch amp Signal 5 2 SM 6299 Rev 1 0 June 2008 77 AnsaldoSTS Union Switch amp Signal 6 PARTS LISTS 6 1 ATT 20 Audio Track Receiver Kits Parts Lists Each kit consists of a complete ATT 20 unit for series mode application and the Cable Compensating PCB Table 6 1 20 Unit Kits US amp S Kit Part No ATT 20 Unit Cable Compensating Application X451052 3907 N451052 3904 N13100201 Series X451052 3908 N451052 3905 N13100201 Series X451052 3909 N451052 3906 N13100201 Series 6 2 ATT 20 Audio Track Transceiver Units Table 6 2 20 Unit Only US amp S Part No Frequency KHz Application N
10. e rt o 2 7 3 FUNCTIONAL DESCRIPTION 3 1 94 General zu eet eta er t s ct tm t mtt 3 1 3 2 Shunt Mode Track ertet o ath 3 1 Series Mode Track Circuit 3 1 3 4 Detailed Circuit Descriptioni oe eee age Le uitae 3 1 93 415 ette Te E Pet EUH PURI edd 3 1 3 4 2 ced tetas 3 2 4 FIELD MAINTENANCE nnaman 4 1 AA e ri ral eran etum m o e e P eei 4 1 4 2 Test Equipment cy age ae ashaka ak Qa de pte au dude 4 1 4 3 General Checks teo meto em oreet dere m hapi erasum mcd 4 1 4 4 Shunt Mode Checks 2 002202 0 0 0 00 00 l 4 1 4 5 Series Mode Checks etre er aired oer ken dd 4 3 5 lt 2 yaaa as 5 1 SM 6299 Rev 1 0 June 2008 iii lt N 77 AnsaldoSTS Table of Contents Union Switch amp Signal 6 PARTS LISTS 6 1 6 1 ATT 20 Audio Track Receiver Kits I
11. positive and N negative to their respective battery bus or supply terminals Lightning arrestor USG A N451552 0101 should be across ripple filter terminals B and N Refer to Section 2 9 for the details on lightning protection If the ATT 20 is to be powered from an electronic supply this supply should be capable of delivering 1 0 ampere at 12 Vdc on the ATT 20 side of the surge ripple filter and be dedicated to the ATT 20 it is powering SM 6299 Rev 1 0 June 2008 lt 7 AnsaldoSTS Y Union Switch amp Signal Application Installation and Adjustments 2 7 2 Shunt Mode Adjustment a Connect a hardwire shunt across the rails outside the defined block at the desired ring by distance from the ATT 20 receiver track connections terminals 5 and 6 Table 2 2 shows typical ring by parameters for 3 0 ohm 1000 ballast and 0 1 ohm adjustment shunt Note The adjustment shunt mentioned below is not a hard wire shunt This shunt must accurately represent the desired shunting sensitivity b Adjust the ATT 20 transmitter output level through the access hole in the top cover until the relay is energized Remove the hardwire shunt from the rails Place an adjustment shunt across the rails at the receiver connection not the ring by distance The relay should drop out A compromise between the shunting sensitivity adjustment shunt and ring by distance will be achieved per application Remove the adjus
12. 451052 3901 12 28 Shunt N451052 3902 15 00 Shunt N451052 3903 20 00 Shunt N451052 3904 12 28 Series N451052 3905 15 00 Series N451052 3906 20 00 Series Table 6 3 Miscellaneous Application Units Item US amp S Part Number Application Secondary Surge Protector N451522 0525 USSP 21 Between ATT 20 unit and track Surge Ripple Filter N451890 0301 Between ATT 20 power input and DC source Lightning Arrestor N451552 0101 Across battery terminals of Surge Ripple Filyer Cable Compensating PCB N1310 0201 SM 6299 Rev 1 0 June 2008 6 1 Parts Lists 6 3 ATT 20 Audio Track Receiver Parts List A 77 AnsaldoSTS Union Switch amp Signal The following tables contain a complete parts list for ATT 20 Audio Track Transceiver units N451052 3901 through 3906 Refer to Figure 6 2 Table 6 4 20 Unit Parts List Item Part Number Description Quantity 5 Refer to Table 6 5 CHASSIS 1 EA 10 438872 COVER 1 EA 15 Refer to Table 6 5 PCB ATT 20 TRANSMTTER 1 EA 20 Refer to Table 6 5 PCB ATT 20 RECEIVER 1EA 25 M181829 4 WAY BLOCK 1EA 30 J5252720110 SCREW 10 32X5 8 SST 2EA 35 4047733 WASHER 10 STEEL LOCK MED 2EA 40 J048172 NUT 10 32 HEX STEEL 2EA 45 J047818 WASHER 17 64X9 16 COP 40 EA 50 J480300 NUT 14 24 HEX BRASS NP 16 EA 55 J480301 NUT 14 24 HEX BRASS 16 EA 60 J525111 SCREW 8 32X1 1 4 RD HD STEEL 4
13. 6 1 6 2 ATT 20 Audio Track Transceiver 6 1 6 3 ATT 20 Audio Track Receiver Parts 6 2 6 4 Cable Compensating PCB Parts List 6 5 7 RAIL TEAM AND TECHNICAL SUPPORT u u 7 1 List of Figures Figure 1 1 ATT 20 DIMENSIONS u O 1 3 Figure 2 1 Shunt Mode Track Circuit Application U 2 1 Figure 2 2 Series Mode Track Circuit Application U 2 2 Figure 2 3 Lightning Arrester and Surge Ripple Filter for Shunt Mode Application 2 8 Figure 2 4 Lightning Arrester and Surge Ripple Filter for Series Mode Application 2 9 Figure 3 1 Transmitt6er PCB Schematic Diagram sse 3 3 Figure 3 2 Receiver PCB Schematic 3 4 Figure 4 1 ATT 20 Test Circuit for Shunt Mode Application 4 2 Figure 4 2 ATT 20 Test Circuit for Series Mode Application sene 4 3 Figure 6 1 ATT 20 Wiring enne enses 6 3 Figure 6 2 AT T 20 Pans i sth nat teet e cete P pee tates 6 4 Figure 6 3 Cable Compensating PCB Parts Layout and Schematic 6 5 List of Tables Table 1 1 Adjacent Fre
14. A g AnsaldoSTS iooorecnnology Drive Pittsburgh PA 15219 Union Switch amp Signal 645 29006 SM 6299 ATT 20 Audio Track Transceiver US amp S Part No N454052 3901 through N454052 3906 Installation mor Operation TX ra Troubleshooting FREQ Copyright 2008 SM 6299 Rev 1 0 Union Switch amp Signal Inc June 2008 ay 77 AnsaldoSTS Union Switch amp Signal Notices Proprietary Notice This document and its contents are the property of Union Switch amp Signal Inc hereinafter US amp S This document has been furnished to you on the following conditions no right or license under any patents or any other proprietary right in respect of this document or its content is given or waived in supplying this document This document or its content are not to be used or treated in any manner inconsistent with the rights of US amp S or to its detriment and are not to be copied reproduced disclosed to others or disposed of except with the prior written consent of US amp S Important Notice US amp S constantly strives to improve our products and keep our customers apprised of changes in technology Following the recommendations contained in the attached service manual will provide our customers with optimum operational reliability The data contained herein purports solely to describe the product and does not create any warranties Within the scope of the attached manual it is impossible to take i
15. ON When using the shunt track circuit configuration do not repeat the use of the same frequency unless circuits are isolated by at least two 2 insulated points Where less ring by is desired keep the track circuit length to a minimum and use the shortest possible track leads Refer to Figure 2 1 and Table 2 2 for shunt track circuit application 2 7 1 Shunt Mode Installation a 2 4 Connect transmitter terminals 3 and 4 to terminals 3 and 4 of the USS 21 surge suppressor Continue the cabling to the track from terminals 1 and 2 of the USSP 21 Repeat the above procedure for cabling receiver input terminals 5 and 6 to the rails All transmitter and receiver cables must be 9 AWG or heavier and used as a twisted pair Ensure the combined lengths of the transmitter and receiver cables do not exceed 500 ft Also do not exceed block lengths of 300 ft Connect terminals 7 relay and 8 relay to the relay The recommended relay to be used with the ATT 20 is a PN 150B 400 ohm plug in type US amp S Part No N322500 701 If the ATT 20 is to receive its DC power from a battery or constant potential rectifier supply CPR or an electronically regulated supply a surge ripple filter Part No N451590 0301 must be used as follows on the next page Connect terminals 1 and 2 of the ATT 20 to respective DC and DC terminals of the ripple filter Jumper terminals 2 to N on the ripple filter and cable terminals B
16. d repeat steps a and b If the relay still does not pick up replace it with another PN 150B 400 ohm coil US amp S Part No N322500 701 c Ifthe relay does pick disconnect the circuit of Figure 7 Measure the open circuit volt age across terminals 3 and 4 The voltage should be equal to or greater than 2 3 Vrms If this voltage should be equal to or greater than 2 3 Vrms reconnect the circuit of Figure 7 Adjust the transmitter level so that it will only pick the relay Measure the voltage across terminals 5 and 6 receiver input This voltage should be 70 mVrms 14 mVrms If not replace the ATT 20 unit SM 6299 Rev 1 0 June 2008 4 1 7 AnsaldoSTS Field Maintenance Union Switch amp Signal ATT 20 lt 1 3 5 12V 5 0 OHM 10 BATTERY OHM lt OP 4 6 8 PN150B RELAY Figure 4 1 ATT 20 Test Circuit for Shunt Mode Application The tests performed in Section 4 3 verify proper operation of the ATT 20 unit in a shunt mode application If the track circuit installation still does not work properly proceed to troubleshoot the cabling connections and peripheral equipment associated with the track circuit 4 2 SM 6299 Rev 1 0 June 2008 5 77 AnsaldoSTS Union Switch amp Signal Field Maintenance 4 5 Series Mode Checks a Connect the ATT 20 as shown in Figure 4 2 b Turn the transmitter level adjustment fully clockwise If the relay picks proceed to step c listed be
17. ed signal Resistor R13 is selected to provide an input sensitivity of 70 mVrms modulated signal Transformer T2 and capacitor C9 form the demodulated filter Transistors Q4 and Q5 are con figured as an emitter follower which buffers the demodulated signal Capacitors C11 and C12 along with diode D3 and D4 form a voltage doubler This doubler produces a negative DC voltage which drives a level detector The level detector consists of resistor R17 and diode D5 Once in conduction D5 provides the feedback path necessary for Q6 and its associated circuitry to behave as an oscillator The oscillator frequency is approximately 25 KHz The output of the oscillator is buffered by transistor Q7 and 10 Transistors Q8 and Q9 amplify the signal Diodes D7 and Q11 along with capacitors C17 C8 form a voltage doubler They also rectify and filter the signal to provide a negative DC voltage to drive an external relay The Q11 circuit decreases relay drop away time in lieu of the standard 2 diode voltage doubler circuit Inductors L1 L2 L6 and L7 along with capacitors C19 and C7 provide RFI rejection Capacitor C10 filters the power bus 3 2 SM 6299 Rev 1 0 June 2008 N 77 AnsaldoSTS Union Switch amp Signal Functional Description 3B3 0010 00 FL B Y gt n T TPA 1 12 T Qi 2N3117 R3 3 Box Rk lt D1 D2 Lvasso
18. he unit for making external connections Refer to Table 2 1 Table 2 1 Terminal Assignments Terminal No Description 1 Battery Battery Transmitter Lead Transmitter Lead Receiver Lead Receiver Lead Relay INID O AJOJN Relay Internal wiring is accessed through a grometted hole in the faceplate Also located on the faceplate is an access hole which is intended for setting transmitter gain This is a simple adjustment and can be accomplished with a screwdriver 2 5 Mounting Requirements A convenient mounting bracket which is an integral part of the case provides four holes spaced 2 1 4 x 8 1 2 apart to facilitate wall shelf or rack mounting 2 6 General Considerations a Track leads to the transmitter and receiver must be a 9 AWG or heavier twisted pair b Power supply must be 9 8 15 2 Vdc and capable of supplying 1 ampere A surge ripple filter US amp S Part No N451590 0301 must be used between any supply and the ATT 20 Power supply ripples must not exceed 1 0 Vpp c Use higher frequency units when less ring by is desired d Provide lightning protection per Section 2 9 e The relay recommended to be used with ATT 20 is a vital PN 150B US amp S No N322500 701 400 ohm plug in type SM 6299 Rev 1 0 June 2008 2 3 mA w 5 7 AnsaldoSTS Application Installation and Adjustments Union Switch amp Signal 2 7 Shunt Mode Operation CAUTI
19. low If the relay does not pick check the relay connections for proper polarity and open circuits If the relay connections are good then replace at ATT 20 with a unit of the same frequency and then repeat steps a and b If the relay still does not pick replace the relay with another PN 150B 400 ohm coil US amp S Part No N322500 701 c Ifthe relay picks disconnect the circuit of Figure 8 Measure the open circuit voltage across terminals 3 and 4 This voltage should be greater than or equal to 0 4 Vrms Replace the ATT 20f the open circuit voltage is less than 0 4 Vrms But if this voltage is greater than or equal to 0 4 Vrms reconnect the circuit which appears in Figure 8 Then adjust the transmitter level to only pick the relay Measure the voltage across terminals 5 and 6 receiver input This voltage should be 70 mVrms 14 mVrms If not replace the ATT 20 unit The tests performed in Section 4 4 verify proper operation of the ATT 20 unit in a series mode application If the track circuit installation still does not work properly proceed to troubleshoot the cabling connections and peripheral equipment associated with the track circuit ATT 20 O01 3O N A A O5 70 12V 1 0 OHM BATTERY 4 V 40 O6 80 PN150B RELAY Figure 4 2 20 Test Circuit for Series Mode Application SM 6299 Rev 1 0 June 2008 4 3 AS 77 AnsaldoSTS Field Maintenance Union Switch
20. nto account every eventuality that may arise with technical equipment in service Please consult your local US amp S sales representative in the event of any irregularities with our product We expressly disclaim liability resulting from any improper handling or use of our equipment even if these instructions contain no specific indication in this respect We strongly recommend that only approved US amp S spare parts are used as replacements SM 6299 Rev 1 0 June 2008 i 2 7 AnsaldoSTS Revision History Union Switch amp Signal Revision History REV DATE NATUREOFREVSIN DATE NATURE OF REVISION O Aprit997 niaise Revised to current template Updated parts lists and drawings Incorporated ECO EE 1223 2 00 June 2008 Miscellaneous minor grammatical changes Proof read comments ii SM 6299 Rev 1 0 June 2008 77 AnsaldoSTS Union Switch amp Signal Table of Contents Table of Contents 1 GENERAL INFORMATION J 1 1 zt INTOGUCUON e a n Rt e ttti te 1 1 1 2 Physical Descrptlor ie iere e er le EI hd eau 1 1 19 lt uH 1 1 1 3 1 Power Requirements s anaa a 1 1 1 3 2 Transceiver Characteristics
21. o cedures should also reveal whether the fault is in the ATT 20 or a related unit or circuit If fault lies with the ATT 20 the ATT 20 should be replaced with a new unit When installing the new unit please make certain to follow all installation procedures outlined in Section II Replacement units may be obtained through the US amp S Sales Office 4 2 Test Equipment True RMS reading DMM Fluke 8010A or equivalent e 5 0ohm 5 watt resistor 196 e 1 0 ohm 5 watt resistor 1 4 3 General Checks a Inspect all leads for breaks and loose terminal connections b Check power supply voltage at terminals 1 and 2 The voltage should be 12 Vdc nominal 9 8 to 15 8 Vdc maximum Ripple voltage should not exceed 1 0 Vpp c Check the fuse on the transmitter circuit board If it is open replace it with a 3 4 Amp fast blow fuse If the fuse is intact disconnect the transmitter and receiver track connections at the unit To test for proper operation in the shunt mode refer to Section 4 4 To test for proper operation in the series mode refer to Section 4 5 4 4 Shunt Mode Checks a Connect the ATT 20 as shown in Figure 4 1 b Turn fully clockwise the transmitter level adjust If the relay picks proceed to step c below But if the relay does not pick check the relay connections for proper polarity and open circuits If the same relay connections are good replace the ATT 20 with one of a unit of the same operating frequency an
22. of the USSP 21 surge suppressor Connect terminals 1 and 2 of the USSP 21 to the track at a point 75 feet from the switch points All cabling from the ATT 20 to the track must be 9 AWG or heavier twisted pair c Connect terminals 7 relay and 8 relay to the relay The recommended relay to be used with the ATT 20 is a PN 150B 400 ohm plug in type Part No N322500 701 d If the ATT 20 is to receive its DC power from a battery constant potential rectifier supply CPR or an electronically regulated supply a surge ripple filter Part No N451590 0301 must be used as follows If the ATT 20 is to be powered from an electronic supply this supply should be capable of delivering 1 0 ampere at 12 Vdc on the ATT 20 side of the surge ripple filter and be dedicated to the ATT 20 it is powering 2 8 2 Series Mode Adjustment without Cable Compensating PCB a Connect a hardwire shunt across the rails 65 feet from the ATT 20 track connections b Adjust the ATT 20 transmitter output level through the access hole in the top cover until the relay is just energized c Remove the hardwire shunt from the rails The adjustment procedure is complete 2 6 SM 6299 Rev 1 0 June 2008 lt 7 AnsaldoSTS T Union Switch amp Signal Application Installation and Adjustments 2 8 3 Series Mode Adjustment with Cable Compensating PCB a Place an O ohm shunt across the track connections at the feed end b Connect an AC voltme
23. ohm shunt mode 1 ohm series mode 1 3 3 Receiver Characteristics Sensitivity 70 mVrms modulated signal 14 mV Input Impedance 7 ohms shunt mode 1 ohm series mode Output Voltage 7 65 Vdc into 400 ohms Table 1 1 Adjacent Frequency Rejection ATT 20 Frequency Adjacent Frequency of Rejection of Adjacent KHZ Concern KHz Frequency dB 12 28 15 0 18 0 12 28 30 0 15 0 18 0 21 0 20 0 27 0 15 0 44 0 20 0 18 0 23 0 Of concern where joint detectors are used 1 2 SM 6299 Rev 1 0 June 2008 77 AnsaldoSTS Union Switch amp Signal 1 3 4 Miscellaneous Reverse battery protection Operating temperature range Maximum block length Recommended Relay Overall Dimensions Mounting Hole Dimensions Weight Terminal Connections lt amp 4 5 8 REF 2 1 4 REF General Information Built in 40 C to 70 C 300 ft shunt mode at 3 ohm 1000 ft ballast 150 ft series mode at 3 ohms 1000 ft ballast PN 150B 400 ohm coil US amp S N322500 701 Refer to Figure 1 1 214 x 812 4 lbs 14 oz AAR 2 1 8 REF 9 4 6 1 16 REF 9 7 5 8 REF BATTERY RCV RELAY B LOWER RAISE RELAY VOLTS AUDIO TRACK SHUNT TRANS MODE MODEL UNT SEN FREQ q UNION SWITCH amp SIGNAL INC PITTSBURGH 15237 2 EE OUS ws TL6 TL5
24. quency Rejection ener nennen 1 2 Table 2 1 Terminal Assignments nennen nennen nennen nnns 2 3 Table 2 2 Ring by Parameters for 0 1 Ohm 4 4 2 0 0001 2 5 Table 2 3 Cable Length vs Frequency U enne nnns nnne en 2 6 Table 6 1 AT T 20 Unit Kits 2m eed ct Ht Ee ie rt d ee date dide da 6 1 Table 6 2 ATT 20 Unit Only ete nct aae tea rt t a 6 1 Table 6 3 Miscellaneous Application Units eene 6 1 Table 6 4 AT 1 20 Unit Parts u toi ee 6 2 Table 6 5 ATT 20 Part Tabulation eee aa ayy wy esa nnn nn nnne 6 3 Table 6 6 Cable Compensating PCB Parts List 6 5 iv SM 6299 Rev 1 0 June 2008 ay 77 AnsaldoSTS Union Switch amp Signal General Information 1 GENERAL INFORMATION 1 1 Introduction This manual provides application installation and maintenance information for the Union Switch amp Signal Audio Track Transceiver Model ATT 20 The ATT 20 is a short range transceiver operating in the audio frequency range of 12 to 20 KHz The high frequency range was chosen to provide sharp block definition The ATT 20 can be used in applications such as highway crossings island circuits switch lock release and general train detection in non electrified and DC electrified territorie
25. r located on the ATT 20 unit This jumper connects the transmitter output terminal to the receiver input terminal The remaining transmitter output lead and the remaining receiver lead are twisted as a pair with each is connected to its respective rail The presence of a train axle across the rails completes the series signal path thus detecting the presence of a train The series mode of operation is a non vital application 3 4 Detailed Circuit Description 3 4 1 Transmitter The transmitter circuit diagram is shown in Figure 3 1 Transistor Q1 and its associated circuitry comprise the modulation oscillator which produces 390 Hz A constant signal level is maintained by Zener diode D1 Transistor Q2 buffers the modulation oscillator Transistor Q7 and its associated circuitry comprise the carrier frequency oscillator Selection of capacitor C3 determines the carrier frequency Transistors Q3 R8 and R13 mix the carrier and modulation signals Resistor R14 provides gain control Inductor L1 capacitor C5 and resistor R17 form a bandpass filter which allows the modulated carrier to pass unaltered by low frequency or higher order harmonic disturbances SM 6299 Rev 1 0 June 2008 3 1 AY 77 AnsaldoSTS Functional Description Union Switch amp Signal Resistor R15 and R19 form a voltage divider which sets the bias for transistor Q4 Capacitor C12 bypasses resistor R19 Transistors Q4 Q5 Q6 and Q8 make up a unity gain amplifier with low ou
26. s In most cases insulated joints are not required and track circuits up to 300 feet in length can be realized Units are available for operation in either shunt mode or series mode applications 1 2 Physical Description The ATT 20 is a single unit transceiver containing separate transmitter and receiver printed circuit boards mounted on a common chassis The chassis is housed in a sheet metal box The top cover of the unit is the faceplate to which AAR terminal posts are mounted 1 3 Specifications 1 3 1 Power Requirements Power Supply Voltage 9 8 15 2 Vdc Maximum Ripple 1 Vpp Load Current 600 mA Fuse 3 4 Amp fast blow SM 6299 Rev 1 0 June 2008 1 1 mA 4 AnsaldoSTS General Information Union Switch amp Signal 1 3 2 Transceiver Characteristics CAUTION The ATT 20 may be operated from a constant potential rectifier CPR supply batteries floating on a CPR or an electronically regulated supply Regardless of the supply used a surge ripple filter US amp S N451590 0301 must be used between the supply and the ATT 20 Transceiver Shunt Mode Output Voltage 1 0 Vrms modulated into a 5 ohm load Series Mode Output Voltage 0 25 Vrms modulated into a 1 ohm load Available Operating Frequencies 12 28 KHz 15 0 KHz 20 KHz Carrier Frequency Tolerance 0 5 96 Modulation Frequency All Units 390 Hz 0 596 Harmonic Output 30 dB at second harmonic with 12 ohm load in shunt mode 7
27. ter Vrms across terminals 5 and 6 on the ATT 20 On the cable compensating PC board adjust the slug in pot core inductor 1 17 until the voltmeter indicates a maximum Note Depending on cable length peaking of the signal might not be possible After adjustment of inductor place a small amount of RTV in the pot core adjuster area d Remove the O ohm shunt e Adjust track circuit as shown above in section 2 8 2 2 9 Lightning Protection Two lightning protection devices are to be used with the ATT 20 The track connections will be made through a USSP 21 secondary surge protection and the battery power supply line will be protected by a surge ripple filter which uses a USG A lightning arrester across the power bus terminals The USSP 21 surge protector is wired to permit line to line protection using a low voltage arrester and line to ground protection using high voltage arresters Internal circuitry of the USSP 21 also includes series line inductors as well as back to back Zener diodes for suppression of low voltage transients The US amp S part no is N451552 0525 The surge ripple filter consists of a series line inductor and a four terminal capacitor with a selenium suppressor diode across its terminals The four terminal capacitor guarantees loss of power to the load should one of the capacitor leads or plates open The line to line arresters used across terminals 1 and 2 of the USSP 21 and terminals B and N of
28. the Surge Ripple Filter are USG A N451552 0101 The line to ground arresters used across terminals 1 and 5 2 and 6 of the USSP 21are USG A N451552 0201 Block wiring diagrams showing the wiring of surge and ripple protection for the ATT 20 in both the shunt and series modes of operation appear in Figure 2 3 and Figure 2 4 respectively SM 6299 Rev 1 0 June 2008 2 7 Application Installation and Adjustments 2 8 SN 77 AnsaldoSTS Union Switch amp Signal SURGE RIPPLE N451590 0301 383000400 N A TERY O OR PO SU WER PPLY TO TO TRACK TRACK 2 1 2 USSP 21 i E USSP 21 SS 3 4 3 4 3 4 5 6 TRANSMITTER RECEIVER ATT 20 1 2 7 8 pc pc RELAY pe ODC DCO FILTER 40 2 LIGHTNING ARRESTER PART NO N451552 0101 QQ TWISTED PAIR Application Figure 2 3 Lightning Arrester and Surge Ripple Filter for Shunt Mode SM 6299 Rev 1 0 June 2008 5 77 AnsaldoSTS Union Switch amp Signal Application Installation and Adjustments TO TRACK ade 5 ussp 21 8 O3 ibi 3 4 6 5 TRANSMITTER RECEIVER ATT 20 1 2 DC DC RELAY m _ ODC DCO B3 25 2 TWISTED PAIR D TO LIGHTNING ARRESTER BATTERY PART NO 451552 0101 OR POWER SUPPLY Figure 2 4
29. tment shunt from the rails The adjustment procedure is complete Table 2 2 Ring by Parameters for 0 1 Ohm Shunting Track Length Total Cable Typical Minimum Ring By Ft Ft Length Ft 42 28 KHZ 15 0 KHz 20 0 KHz 100 100 11 10 9 300 14 14 13 500 19 19 19 200 200 18 18 17 300 21 21 22 500 29 29 33 300 300 30 30 33 400 35 36 41 500 40 43 52 SM 62989 Rev 1 0 June 2008 2 5 5 77 AnsaldoSTS Application Installation Adjustments Union Switch amp Signal 2 8 Series Mode Operation Series track circuit locations operating at the same frequency must be separated by at least two insulated joints A typical series mode application would be at a switch lock Refer to Figure 2 2 for this application 2 8 1 Series Mode Installation a Connect a jumper strap between terminals 4 and 6 on the ATT 20 when the total single conductor cable length from the ATT 20 to the track is less what appears in Table 2 3 below If the cable length is exceeded connect terminals 4 and 6 on the ATT 20 to terminals 1 and 2 respectively on the cable compensating circuit board N131002 01 Table 2 3 Cable Length vs Frequency Suffix No Frequency Total Cable Length Jumper from Cable Compensating N451052 KHz Length x 2 cond PCB to Terminal 3904 12 28 lt 75 feet 3905 15 lt 50 feet T2 3906 20 lt 25 feet T1 b Connect terminals 3 and 5 to terminals 3 and 4
30. tput impedance Diodes D4 D5 D6 and D8 along with resistors R20 and R21 serve to temperature compensate and bias both transistors Q5 and Q6 C13 is a bypass capacitor Capacitor C6 and the primary of T3 couple the signal to the output circuitry Inductor L5 jumper J2 and capacitor C9 from the shunt mode output providing an output impedance of 7 ohms Inductor L6 jumper J1 and capacitor C9 form the series mode output with an output impedance of 1 ohm Diode D7 prevents damage from reverse battery connection Fuse F1 prevents damage from an overcurrent condition Inductors L2 L3 and capacitor C11 provide RFI rejection Capacitors C7 and C10 filter the power bus 3 4 2 Receiver The receiver circuit diagram is shown in Figure 3 2 Capacitor transformer and resistor form a medium Q input filter Jumper positions should be J1 and J3 for both shunt and series mode boards The input impedance is primarily determined by R1 Shunt boards 7 ohms series boards 1 ohm Transistors Q1 and Q2 form a Darlington pair emitter follower which buffers the input signal Resistor R4 and Zener diode D10 provide a fixed bias voltage for Q1 and Q2 Inductors L3 and L4 capacitor C3 C4 and C5 and resistors R6 and R7 together form a high Q bandpass filter Diode D1 demonstrates the signal Resistor R8 and capacitor C6 filter the carrier frequency Transistor Q3 and its associated circuitry form an emitter follower to buffer the demodulat
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