background image

 ATT-20 Audio Track Transceiver 

Copyright 2019                                   SM 6299 Rev. 3, March 2019 

6-6 

10

15

5

20

30

25

35

3B

3.

00

08

.0

0

 

Figure 6-3.  Cable Compensating PCB Parts Layout and Schematic Diagram 

 

 
 
 

Summary of Contents for ATT-20

Page 1: ...99 1000 Technology Drive Pittsburgh PA 15219 645 Russell Street Batesburg SC 29006 ATT 20 Audio Track Transceiver STS USA Part Numbers N454052 3901 through N454052 3906 Installation Operation Troubleshooting ...

Page 2: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 ...

Page 3: ...s not create any warranties Within the scope of the attached manual it is impossible to take into account every eventuality that may arise with technical equipment in service Please consult an STS USA local sales representative in the event of any irregularities with our product STS USA expressly disclaims liability resulting from any improper handling or use of our equipment even if these instruc...

Page 4: ...to current template Updated parts lists and drawings Incorporated ECO EE 1223 2 00 Miscellaneous minor grammatical changes Proof read comments resolved 2 December 2015 Revised Figure 1 1 and Figure 6 1 to add R14 and label Revised Table 6 4 and Figure 6 1 for items 126 and 127 Revised Table 6 5 to correct ATT 20 Unit part numbers 3 March 2019 Hitachi Rail STS Branding ...

Page 5: ... Considerations 2 3 2 7 Shunt Mode Operation 2 4 2 7 1 Shunt Mode Installation 2 4 2 7 2 Shunt Mode Adjustment 2 5 2 8 Series Mode Operation 2 5 2 8 1 Series Mode Installation 2 6 2 8 2 Series Mode Adjustment without Cable Compensating PCB 2 6 2 8 3 Series Mode Adjustment with Cable Compensating PCB 2 7 2 9 Lightning Protection 2 7 3 FUNCTIONAL DESCRIPTION 3 1 3 1 General 3 1 3 2 Shunt Mode Track ...

Page 6: ...3 1 Transmitter PCB Schematic Diagram 3 3 Figure 3 2 Receiver PCB Schematic Diagram 3 5 Figure 4 1 ATT 20 Test Circuit for Shunt Mode Application 4 2 Figure 4 2 ATT 20 Test Circuit for Series Mode Application 4 3 Figure 6 1 ATT 20 Parts Illustration 6 4 Figure 6 2 ATT 20 Wiring Diagram 6 5 Figure 6 3 Cable Compensating PCB Parts Layout and Schematic Diagram 6 6 List of Tables Table 1 1 Adjacent Fr...

Page 7: ... train detection in non electrified and DC electrified territories 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 o...

Page 8: ... Vrms modulated into a 1 ohm load Available Operating Frequencies 12 28 KHz 15 0 KHz 20 KHz Carrier Frequency Tolerance 0 5 Modulation Frequency All Units 390 Hz 0 5 Harmonic Output 30 dB at second harmonic with 12 ohm load in shunt mode 7 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 ...

Page 9: ...ms 1000 ft ballast Recommended Relay PN 150B 400 ohm coil STS USA N322500 701 Overall Dimensions Refer to Figure 1 1 Mounting Hole Dimensions 2 x 8 Weight 4 lbs 14 oz Terminal Connections AAR RCV REF 2 AUDIO TRACK TRANSCEIVER MODEL ATT 20 REF LOWER 6 1 16 2 1 8 8 RELAY REF TL5 TL6 SHUNT MODE UNIT 2 1 4 REF PC NO SER NO FREQ REV 7 5 8 4 5 8 7 REF BATTERY XMT 1 4 5 8 REF 9 4 1 3 RELAY VOLTS TL1 RAIS...

Page 10: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 1 4 ...

Page 11: ...nected by cable directly to the rails The connection is made through surge protectors by twisted line pairs as shown in Figure 2 1 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 sign...

Page 12: ...put 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 75 FEET 60 FEET ADJUSTMENT SHUNT O OHM SHUNT USSP 21 _ TWISTED PAIR ATT 20 1 2 3 ...

Page 13: ...s 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 Track leads to the transmitter and receiver must be a 9 AWG or heavier twisted pair Power supply must be 9 8 15 2 VDC and cap...

Page 14: ...the combined lengths of the transmitter and receiver cables do not exceed 500 ft Also do not exceed block lengths of 300 ft 2 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 STS USA Part No N322500 701 3 If the ATT 20 is to receive its DC power from a battery or constant potential rectifier supply CPR or an elect...

Page 15: ...e top cover until the relay is energizes 3 Remove the hard wire shunt from the rails 4 Place an adjustment shunt across the rails at the receiver connection not the ring by distance The relay should deenergize A compromise between the shunting sensitivity adjustment shunt and ring by distance will be achieved per application 5 Remove the adjustment shunt from the rails The adjustment procedure is ...

Page 16: ... 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 4 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 5 If the ATT 20 is to receive its DC power from a battery constant p...

Page 17: ...ails 65 feet from the ATT 20 track connections 6 Adjust the ATT 20 transmitter output level through the access hole in the top cover until the relay is just energized 7 Remove the hardwire shunt from the rails The adjustment procedure is complete 2 9 Lightning Protection Block wiring diagrams showing the wiring of surge and ripple protection for the ATT 20 in both the shunt and series modes of ope...

Page 18: ...r 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 the Surge Ripple Filter are USG A N451552 0101 The line to ground arresters used across terminals 1 and 5 2 and 6 ...

Page 19: ... TRACK 1 2 5 6 3 4 USSP 21 3 4 TRANSMITTER 5 6 RECEIVER ATT 20 _ _ _ DC DC DC DC RELAY 1 2 7 8 SURGE RIPPLE FILTER N451590 0301 4 2 B N LIGHTNING ARRESTER PART NO N451552 0101 TO BATTERY OR POWER SUPPLY TWISTED PAIR 3B3 0004 01 Figure 2 3 Lightning Arrester and Surge Ripple Filter for Shunt Mode Application ...

Page 20: ...TO TRACK 1 2 5 8 USSP 21 3 4 3 4 6 5 TRANSMITTER RECEIVER ATT 20 1 2 7 8 DC _ DC _ RELAY TWISTED PAIR _ DC DC 4 B N 2 TO BATTERY OR POWER SUPPLY LIGHTNING ARRESTER PART NO N451552 0101 3B3 0005 01 Figure 2 4 Lightning Arrester and Surge Ripple Filter for Series Mode Application ...

Page 21: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 2 11 ...

Page 22: ......

Page 23: ... Mode Track Circuit As illustrated in Figure 2 2 the transmitter and receiver are wired in series via a jumper 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 ...

Page 24: ...e 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 demodulated signal Resistor R13...

Page 25: ... C11 TP4 L3 Q4 22uf R6 C1 1 0uf R15 1K L1 1K 1328T LVA450 D1 390K R3 C13 3 0K R19 1N914 1N914 10K R16 TP3 C4 1M R14 33K R13 1N914 D3 TP1 3 6M R22 470K R12 TAB C3 10K R8 2N3964 Q7 R7 10K 258T 26T 15uf C2 8 2K R11 10K R5 5 1K R4 5 1K 3 3K R9 R10 Q1 T1 R1 332T D2 1N914 TAB 6 8uf 10K R23 C5 TAB R17 1N914 2N3117 47uf C12 2N3117 Q3 2N3117 Q2 TP2 TL2 POWER 1 1 2 A F1 TL1 B 1N914 TRACK TL5 TRACK 47uf C7 0...

Page 26: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 3 4 ...

Page 27: ... TRACK TRACK 1 5K T2 R15 1K R14 TBD R13 2N3117 Q3 10K R12 Q4 47uf C10 47K R11 0033uf TAB C5 1N4936 5uf 01uf C7 R3 2K C18 D1 C8 R10 D2 1K 1N914 C D4 1N4003 POWER C12 10uf TL3 B A 02uf C6 TAB TAB L3 TP1 C15 1uf R21 2 4K 10K R4 2ND J4 J3 R20 L2 TL2 C1 L1 Q10 24K R25 2K R26 20 R28 VSK130 D7 680 2N4037 R27 Q9 C17 2N3053 Q8 D6 2N2270 TP5 C11 2N2270 Q5 B RELAY 200K R8 56uf C14 270K R19 027uf C13 2K GND T...

Page 28: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 3 6 ...

Page 29: ...ections 2 Check power supply voltage at terminals 1 and 2 The voltage should be 12 VDC nominal 9 8 minimum to 15 8 VDC maximum Ripple voltage should not exceed 1 0 Vpp 3 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...

Page 30: ...ect the jumper between terminals 4 and 6 Adjust the transmitter level so that it just energizes 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 12V BATTERY _ 1 2 3 4 5 6 7 8 _ PN150B RELAY 1 0 OHM 5 0 OHM ATT 20 3B3 0011 00 Figure 4 1 ATT 20 Test Circuit for Shunt Mode Application The tests performed in S...

Page 31: ...nals 4 and 6 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 20 if the open circuit voltage is less than 0 4 Vrms If the voltage is greater than or equal to 0 4 Vrms reconnect the resistor between terminals 3 and 5 and reconnect the jumper between terminals 4 and 6 Adjust the transmitter level to just energize the r...

Page 32: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 4 4 ...

Page 33: ...AINTENANCE STS USA 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 See Section 7 for contact information ...

Page 34: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 5 2 ...

Page 35: ...nsceiver Units The ATT 20 unit part numbers and descriptions are listed in Table 6 2 Table 6 3 lists other devices that are used in certain ATT 20 applications Table 6 2 ATT 20 Unit Only Part No Frequency KHz Application N451052 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 Ap...

Page 36: ...47733 WASHER 10 STEEL LOCK MED 2 EA 40 J048172 NUT 10 32 HEX STEEL 2 EA 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 EA 65 J047714 WASHER 8 SHPRF LK SS 4 EA 70 J048166 NUT 8 32 HEX STEEL 4 EA 75 M337854 INS TUBING 8 EA 80 J052686 SCREW 8X3 8 RD HD 4 EA 85 J730041 TERM PRE INSUL DIAGR 8 ...

Page 37: ...B 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 3904 12 28 Series R451053 6303 N451605 6405 N451605 6505 N451052 3905 15 Series R451053 6303 N451605 6406 N451605 6506 N451052 3906 20 Series R451053 6303 N451605 6407 N451605 6507 ...

Page 38: ...SIDE 2 AUDIO TRACK TRANSCEIVER MODEL ATT 20 LOWER RELAY TL5 COMP SIDE TL6 R14 SHUNT MODE UNIT 15 PC NO SER NO FREQ REV 4 5 8 7 40 BATTERY XMT 1 75 65 70 60 30 20 3 35 RELAY VOLTS TL1 RAISE 6 10 80 TL2 TL3 TL4 25 85 45 55 50 3B3 0006 01 TL6 TL6 TL5 TL5 Figure 6 1 ATT 20 Parts Illustration ...

Page 39: ...ng Diagram 6 4 Cable Compensating PCB Parts List Refer to Table 6 6 and Figure 6 3 for Cable Compensating PCB STS USA N13100201 parts parts layout and schematic diagram Table 6 6 Cable Compensating PCB Parts List Item Part No Description Quantity 5 N381621 BLOCK TERM 1 EA 10 N13100101 PCB CABLE COMPEN 1 EA 15 J047818 WASHER 17 64X9 16 COP 2 EA 20 J5000970128 SCR SST 1 4 20X1 3 4 2 EA 25 J475120011...

Page 40: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 6 6 10 15 5 20 30 25 35 3B3 0008 00 Figure 6 3 Cable Compensating PCB Parts Layout and Schematic Diagram ...

Page 41: ...CAL 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 hitachirail com ...

Page 42: ...ATT 20 Audio Track Transceiver Copyright 2019 SM 6299 Rev 3 March 2019 7 2 End of Manual ...

Reviews: