AMPLIFIER PLUG-IN UNIT FOR TYPE "EL" CODED CAB SIGNAL EQUIPMENT

Transcription

1 SERVCE MANUAL 5682-G Description, Operation and Maintenance AMPLFER PLUG-N UNT FOR TYPE "EL" CODED CAB SGNAL EQUPMENT Part Number N June, 1977 (Revised July, 1984) C-DN0383 B-7/ UNON SWTCH & SGNAL DVSON AMERCAN STANDARD NC./ SWSSVALE, PA PRNTED N USA

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3 SERVCE MANUAL 5682-G Description, Operation and Maintenance AMPLFER PLUG-N UNT FOR TYPE "EL" CODED CAB SGNAL EQUPMENT Part Number N June, 1977 (Revised July,1984) D0073C-DN0383 B-7/ UNON SWTCH & SGNAL DVSON AMERCAN STANDARD NC./ SWSSVALE, PA PRNTED N USA

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5 UNON SWTCH & SGNAL m SECTON CONTENTS PAGE NRODUCTON 1 \, PURPOSE DESCRPTON Physical Component SPECFCATONS Physical/Mechanical Electrical Master Transformer nterstage Transformer nput Transformer Resistors and Capacitors FUNCTONAL DESCRPTON NSTALLATON GENERAL MOUNTNG NERCONNECT CHECKS AND ADJUSTMENTS V OPERATNG PROCEDURE 6 v FELD MANTENANCE l 5.3 PREVENTVE MANrENANCE Mechanical nspection Electrical nspection TROUBLESHOOTNG Transformers CORRECTVE V SHOP MANrENANCE RECOMMENDED TEST EQUPMEN TEST SET-UP PROCEDURES ADJUSTMENTS V REMOVE AND NSTALL REMOVE AMPLFER NSTALL AMPLFER APPENDX A PARTS LST ].

6 ffi UNON SWTCH & SGNAL LST OF LLUSTRATONS Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure Al. Circuit for Testing mpedance of Master Transformer Circuit for Testing nput Transformer Schematic Circuit Plan of Amplifier Circuit for Operating Test of Amplifier Wiring Diagram of Amplifier Type "EL" Auto Train Control Amplifier A3/4 / ii

7 UNON SWTCH & SGNAL m SEcrlON NTRODUCTON 1.1 PURPCSE The amplifier is a plug-in unit and is part of the Type "EL" COOtinuous Code Cab Signal System manufactured by the Union Switch & Signal Division of American Standard nc. Signals which are picked-up from the rails by the track receiver located on the locomotive are amplified by the amplifier and are then applied to the master relay. \, 1. 2 DESCRPTON The amplifier is housed in a metal case with a carrying handle on the front panel. The bottom of the amplifier case has two metal guide rails for mounting in to an equipnen t rack. The amplifier receives it power by means of rear mounted plug connector that mates with a receptacle located on the equipment rack. The unit is held in place in the rack by means of a front latch and locking screw Physical Length: Width: Height: Weight: 7-7/8 (9-3/32 includes handle) 5-13/16 9-1/32 22 Lbs Component The amplifier consists essentially of two transistors, an input transformer, an interstage transformer, a master transformer and a plug connector. The receiver tuning capacitor, the input transformer, the master transformer and its by-pass capacitor are mounted on a separate base attached to the bottom of the case. The interstage transforner and its tuning capacitor are externally mounted on the cover while the transistors and other circuit components such as resistors, electrolytic capacitor, and terminal strips are attached to the underside of the cover. All units are protected from dirt and moisture by the cover or by separate individual enclosures. Attached to the case are the handle for withdrawing and carrying the unit, the guide bars which engage those on the equipnen t box shelf for proper alignment of the plug connectors, and the name plate. F.ach unit bears its own serial number stencilled on the name plate. Also mounted on the froot of the case are two test jacks, one of which permits measurement of the master relay current and the other, the second stage collector current G, p. l

8 m UNON SWTCH & SGNAL 1.3 SPECFCATONS Physical/Mechanical The plug connector is assembled to the case in a fixture and doweled in place to insure alignment of the plug-in sockets with the plugs on the equipment box shelf plug connector. f it should become necessary to replace a plug connector with a new one, new holes (#52 drill size) for the dowels should be drilled in the plug connector and case in a new locatton. An equipment box shelf can be used as a fixture for properly locating the plug connector on the case. All wires except coil leads are No. 18 B. & S. gauge flexible stranded copper wire with extruded plastic insulation. Leads running from units mounted on the cover to units mounted on the case ar~ left sufficiently long and are cabled so that the cover can be removed and inverted beside the case for convenience in working on the amplifier. / Electrical Master Transformer The resistance of the primary and secondary should be 560 ohms and 4.4 ohms+ 10%, respectively. The core sections are clamped together against non-ferro'ii"s metallic spacers (nominal thickness - O. 003"). The impedance of the secondary winding with the primary open, as measured in the circuit of Figure 1, should not be less than 470 ohms nor more than 530 ohms. Cores are clamped together by phosphor bronze bands. The coil and core assembly is held to the mounting bracket by the same type bands. Since the application of these bands requires special tools, the master transformer, including mounting bracket, should be removed from the amplifier, carefully packed and returned to the Union Switch & Signal Division, Swissvale, Pennsylvania, when repair or readjustment is required. WESTON 0 75 SCALE MODEL155 A.C. MLLAMMETER (READNG SHOULD BE BETWEEN 47 AND 53 M.A.) HGH MPEDANCE VOLTMETER p R ~ (OPEN) A R y V- 25 VOLTS 1 60 CYCLES Figure 1. Circuit for Testing mpedance of Master Transformer 5682-G, P 2

9 UNON SWTCH & SGNAL m nterstage Transforner The air gap of the interstage transforner is carefully adjusted at the factory so that the secoodary is resonant at 100 cycles with the mfd. capacitor. nasmuch as this tuning and adjustment requires special equipment and test frequencies difficult to obtain, the interstage transformer should be removed fran the amplifier, carefully packed and returned to the union Switch & Signal Div isioo when repair or retuning is required nput Transforner The resistance of the primary and secondary should be 22 ohms and 1.75 ohms+ 10%, respectively. The impedance of the primary, as measured in the circuit-of Figure 2, should not be less than 2550 ohms. The open circuit voltage of the secoodary should be 0.09 volts + 5%. 100,v ±1% K:!:5% S P SHOULD TUNE WTH- N VALUES OF CAPACTY SHOWN..20MFD TO.22MFD. ~~~~--SECONDARY 2S V-0.9 VOLTS, 100 CYCLES--- VR VOLTS MAX. Figure 2. Circuit for Testing nput Transforner Resistors and Capacitors Measured values of resistance and capacitance should be within 10% of the value indicated en t.l-ie schematic circuit, Figure 3. An exceptioo to this is the 250 mfd. capacitor (C4, Figure 3), whose capacitance may be between 225 mfd. and 500 mfd G, P 3

10 m UNON SWTCH & SGNAL 0 «ct c, - ll) 2 0 u Cl... u z: 0 "' i 0 u... Lii c:, ::, 0::... a:. ::, )..,... g :r 0...,..J f') i---- Cl oona. (' - - ' g J},.._ <3) N u _,,, U) - q- u 0 t:o t; g c\l u, N ~ u \tl ~ '-'..., N CJ) / l- (\J... er "-'.. \'.; A."'. "' a. l ~ u.. CC 1\V1 c..> A Figure 3. Schematic Circuit Plan of Amplifier 5682-G, p. 4

11 UNON SWTCH & SGNAL m SECTON FUNCTONAL DESCRPTON The receiver input is tuned to 100 Hertz by means of a fixed capacitor in series with the input transformer. The circuit contains two silicon N.P.N. transistors and the amplifier operates on 32 volts de. ' ' The first stage transistor is biased for class A operation. The signal from the secondary of the input transformer is applied between the emitter and base. The collector of this transistor is connected to the primary of the interstage transformer, the secondary of which is connected to the emitter of the second stage transistor. This transistor is not biased thus operating as Class B, and serves as a detector stage, with its collector feeding the primary of the master transformer. During the off period of the code cycle, no current flows in the master transformer primary circuit. During the on period of the code cycle, when current is flowing in the rails, the collector current rises to a pre-determined value. The result is that collector current flows in the primary winding of the master transformer when alternating current is flowing in the rails and ceases to flow when the rail current is interrupted by the code transmitter. The rise and fall of current in the primary winding of the master transformer causes alternating current of code frequency to flow through the low-voltage winding and the master relay connected to it. SECTON NSTALLATON 3.1 GENERAL The amplifier is one of 4 units that mount in an equipment rack located in the equipment box installed on the locomotive. 3.2 MOUNTNG The base of the amplifier case has guide bars designed to engage other guide bars on the rack in the equipment box. t is held securely in place by means of a front latch and thumb screw. 3.3 NTERCONNECT Select the correct location on the rack in the equipment box and properly align the amplifier on the guide bars then push forward with a slow but firm motion to prevent possible damage to the rear plug, until the plug at the rear of the amplifer mates with the receptacle on the rack. Secure the unit by means of the front latch and tighten the thumb screw G, P 5

12 UNON SWTCH & SGNAL 3.4 CHECKS AND ADJUSTMENTS Refer to Section V for testing procedures. SECTON V OPERATNG PROCEDURE There are no operating controls. The bias voltage for the pick-up value is set by means of an adjustment potentiometer and when the value is found the potentiometer is locked in this position.. SECTON V FELD MANTENANCE 5.1 PREVENTVE MANTENANCE Mechanical nspection Carefully examine every part of the assembly for improperly soldered joints, loose screws and nuts, damaged insulation and note that the lead wires are so arranged and cabled that they will not be pinched when the cover is applied to the case Electrical nspection The amplifier should be given a ground test by measuring the resistance between each terminal on the plug connector and the case, using an ohmmeter set on its highest resistance scale. The insulation resistance should be greater than 20 megohms. 5.2 TROUBLESHOOTNG f the amplifier is suspected of being faulty, do the following: a) nspect the amplifier unit and make sure it is properly plugged into the base receptacle on an equipment box shelf. b) Measure the de supply voltage. t should be 32 volts de. c) nsert a code modulator unit and a master relay into their respective positions on the same equipment box shelf. Connect the shelf and receiver circuits together, then make the connections to the de power supply as shown in Figure G, p. 6

13 UNON SWTCH & SGNAL m t-~~~~~~~~~~~~~+32 TYPE EL EQUPMENT BOX RACK t-~~~~~~~~~~~~~-32 Tl TC 110 VOLTS,100 CYCLES TC Tl ' ' OHM RALS Figure 4. Circuit for Operating Test of Amplifier d) 1) Procedure foe receiver units having test jacks on the front panel: The test jacks will accept a standard phone plug. The phone plug should have teat leads long enough to make connections to a milliameter having current ranges large enough to accommodate the tests. Connect the lead from the tip of the plug to the positive terminal of the meter when making measurements. 2) Procedure for receiver units without test jacks on the front panel: (A) Reoove wire frc:in pin seven on plug connector al'ld O(>nnect a 0-lSma de milliameter (refer to section s. 2, step e). (B) Remove wire from terminal ST on PCB and connect a zero center type de milliameter (re for to section s. 2, step g) G, P 7

14 UNON SWTCH & SGNAL e) With the meter plug inserted into the right hand Jack, and current in the rails, read the value on a 0-15 ma de millimeter. This reading should be in the normal direction at the 180-code rate. f) Remove current from rails and the reading on this meter should be zero. g) Connect the meter plug leads to a zero center type de milliameter and insert the plug into the left hand jack. Apply current to the rails and the meter deflections should fluctuate on either side of zero. h) Set the pick-up adjustment potentiometer midway between maximum and m1n1mum and apply the de supply voltage of 32 volts. Measure the amplifier pick-up value which should be within the limits of 0.26 and 0.35 amperes. i) Reduce pick-up to m1n1mum value obtainable with the pick-up adjustment potentiometer. The master relay should continue to operate without noticeable distortion when the rail current is raised to approximately 10 times the normal pick-up value. f the master relay fails to operate with any reasonable value of rail current, replace the amplifier with one known to be operating properly. f the second amplifier restores proper operation, then it can be presumed that the defect is in the first amplifier and not in the circuits external to the amplifier. j) Set the rail current at 0.5 amp and measure the master relay current by means of zero-center milliammeter connected to a phone plug insertea in the left-hand test jack. f the meter deflections are above 20 ma to right and left while the master relay does not operate, the trouble 1s in the master relay, which should be replaced. k) f there is no current in the master relay winding, pull out the code modulator until its plug connection is open, move the plug to the right-hand jack and set the rail current at 0.5 amp. The normal reading in this circuit is approximately 5. 5 ma. f a reading of substantially this value is obtained, the trouble is in the master transformer or the 2 mfd. capacitor. The master transformer may be short circuited, its secondary may be open or the capacitor may be shorted. 1) f, on the other hand, no current reading is obtained in this circuit, the trouble may be located by measuring the ac voltages at the transistor terminals using a high impedance voltmeter. These voltages should be approximately the values given in Table 1, with the pick-up adjustment potentiometer in the minimum pick-up position G, P 8

15 UNON SWTCH & SGNAL m Table Terminals 1st Stage - Emitter and Base Voltage o.oos 1st Stage - Collector and Base nd Stage - Emitter and Base 0.80, 2nd Stage - Collector and Base Transformers A voltage reading varying greatly from that given in Table indicates that the trouble is in a circuit element connected in the circuit at the point where the voltage was measured. f either the input transformer or master transformer is suspected, it should be tested in accordance with instructions given in Section. Since there are no instructions for testing the interstage transformer, it may be checked by replacing it in the amplifier by another one known to have the proper characteristics CORRECTVE f it has been determined that the amplifier is not operating properly then the unit should be repaired at the shop. Refer to Section V, Shop Maintenance. SECTON V SHOP MANTENANCE 6.1 RECOMMENDED TEST EQUPMENT Multimeter (volt-ohm-milliameter) (Simpson 260 or equivalent) Zero center de milliammeter Variable auto transformer Standard phone plug High impedance voltmeter 6. 2 TEST SET-UP A test set-up similar to that of Figure 4 is required to test the amplifier in the shop G, P 9

16 UNON SWTCH & SGNAL 6. 3 PROCEDURES Check all components to be sure they meet the values given in the electrical specifications in Section. Replace any component that does not meet the required values as shown in the parts list. Refer to the schematic diagram in Figure 3, and the wiring diagram in Figure 5 to locate components Using the test set-up in Figure 4, follow the procedures given in Section v f the amplifier proves to be defective then additional testing is required Temporarily replace the transistors with new ones and return the amplifier to the test set-up f it is found necessary to replace a transistor, great care must be exercised when soldering the transistor leads to the terminal strip. These leads must be handled carefully in order to prevent breakage at the point where they emerge from the transistor. Also, in order to prevent overheating the transistor when soldering the leads, the lead wires should be held by a pair of pliers at a point between the transistor and the soldered joint. 6.4 ADJUSTMENTS Refer to Figures 5 and A-1 for location of components and controls. When a new transistor is placed in the amplifier, the first stage collector current should be measured and, if necessary, the first stage bias readjusted to set this current to the proper value. To measure this current, disconnect the lead connected to the SCl-C terminal on the 10-way terminal strip. (This lead is attached to the terminal strip by a ~mall screw). Then connect a 10 or 15 ma de milliammeter between this lead and the terminal with the positive terminal of the meter connected to the lead. With exactly 32 volts de applied to the amplifier, adjust potentiometer P2, mounted on a bracket inside the cover, until the milliammeter reads 6 ma. Wait one minute and, if the current has changed, reset it to 6 ma and tighten the lock nut on the potentiometer. Then remove the meter and reconnect the lead to the terminal strip. Always remove the de power from the amplifier before making any changes in the wiring G, p. 10

17 UNON SWTCH & SGNAL m. c- -, llf!d '! O '.~-----t------:::::~~::~-~~j--=n::-10::-_=::~---_ , J >(' st-6 :::o <110 r--~_s' 6 f ai6 ~..+---J---<_J ffi l + - -_-:-_-ll)-4(:..-:..:.._. ~ Oll ' ~t.. r-t-t <=~ - rr -- ' fi3... ffi ~ ~----, ' ---,J,_, - ~...,--r CD D ~~o ~ t:-..::..:-==========-=-==:--- - :!) _..,-----',---- &. ~' '---- ~ r!1 uj LJ - -T CJ Hl--+-1 H J....J,~ ' (.) Drawing C50004 Sh. 7A, Rev. 10 Figure 5. Wiring Diagram of Amplifier 5682-G, p. 11

18 ffi UNON SWTCH & SGNAL SECTON V REMOVE AND NSTALL 7.1 REMOVE AMPLFER The amplifier is a plug-in unit with a handle on the front and guide bars on the bottom of the case. The bars engage other bars on the equipment box shelf to insure proper alignment of the plug connector, located at the rear of the amplifier, with the receptacle on the equipment shelf. The amplifier is held in place by means of a clamp with front locking screw. To remove the unit, loosen the front locking screw on the clamp and release the clamp. Grasp the handle and pull to disengage the amplfier, then remove it from the equipment box shelf. 7.2 NSTALL AMPLFER Locate the proper position that the amplifier will occupy on the shelf in the equipment box. Engage the guide bars on the bottom of the unit with those on the equipment box shelf and push forward slowly but firmly until the plug connector at the rear of the unit engages the receptacle on the equipment shelf. Set the clamp in place and tighten the screw on the clamp to secure the amplfier G, p. 12

19 SERVCE MANUAL 5682-G Appendix A Parts List AMPLFER PLUG-N UNT FOR TYPE "EL" CODED CAB SGNAL EQUPMENT Part Number N June, 1977 (Revised July, 1984) C-DN0383 B-7/ UNON SWTCH & SGNAL DVSON AMERCAN STANDARD NC./ SWSSVALE, PA PRNTED N USA

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21 UNON SWTCH & SGNAL m Type "EL" AUto Train Control Amplifiec, N See Figure Al TEM DESCRPTO~ PART NUMBER ' Case Handl-e Screw, Machine #6-32 x 7/16 OTal 00. Countersunk (4 Req 'd.) Lockwasher, 16 Plain Steel (12 Req'd.) Nut, Hex (12 Req'd.) Master Transformer (T3) Screw, Ma..::hine 1/4-20 x 7/16 Rd. 00. (4 Req'd.) lj)ckwasher, 1/4 Plain Steel ( 1-1/ 16 x 1-1/ 16) ( 6 Req 'd ) nput Filter (T2) Bcacket, Capacitor Mounting Lockwasher, ita Pl a in Steel ( 22 Req 'd.) Nut, Hex (12 Req'd.) S.:>cket Washer (8 Req 'd.) Bracket Poten tiome te r. Ser ew, Machine #8-32 x 5/8 Rd. 00. (6 Req 'd.) Clamp Cable Screw, #6-32 x 1/2 Rd. 00. Mach. Stl. Cover Name Plate Washer Potentiometer 10,000 Cbms (Pl) Screw, Machine i6-32 x 3/8 Fillet 00. (5 Req'd.) Washer ( 6 Req 'd.) PCB, Cab Signal llmpl. capacitor, MFD 100 Vdc (C2) interstage Transformer (Tl) Screw, Machine x 7/16 Rd. 00. (4 Req'd.) Grommet Filter Cover Screw, Machine x 5/16 Rd. 00. (10 Req'd.) nspection Record Plate Screw, Machine i6-32 x 3/16 Rd. 00. (4 Req'd.) Spacer (5 Req'd.) Ser ew, Machine x 3/ 4 Rd. 00. (4 Req 'd.) Terminal Strip Lockwasher, i4 Plain Steel (2 Req 'd.) Rollpin (2 Req'd.) Screw, x 5/16 Lockwasher, ilo Shake Steel (8 Req 'd.) Washer (8 Req 'd.) Name Plate R J J J J N J J N M J J M Ml52389 M332856,T J052602, J M J M J J Mll3126 N J N J J N J J J Ml05831 J N J J J507268, M M G, p. A-1

22 m UNON SWTCH & SGNAL Par. ts r.,i..,3 t Cont'd. ltem OESCRlPT!ON PART NUMBER Screw, Self-Tapping, i2 x 3/16 Binding Hd. {2 Req'd.) Capacitor, 2.0 MFD 600 Vdc (Cl) Plate, Base Capacitor, TUnn ing Nut, Hex 1/4-20 (2 Req'd.) Diode Strip, Terminal Capacitor, 250 MFD 50 Vdc (C5) Clamp, Cable Ser ew, Machine i6-32 x 3/8 Rd. Hd. insulation Potentiometer, 250 <llms, 2W (P2) (Not Shown) Resistor, 1500 Ohms, lw ('Rl) (Not Shown) Res is tor, 4 70 <llms, lw (R4) (Not Shown) Res is tor, 62K Ohms, lw (R6) (Not Shown) Resistor, 1500 <llms, lw (R7) (Not Shown) J J M J J J N N J700588, M392296, J J J J G, p. A-2

23 UNON SWTCH & SGNAL m ;;... --=l;r=-~---= --===-;!-,,.--~ L J L J, '; ' 11 n ~ ' '!!!1!f.., ~-~ ---@~~)JJ...;: Drawing Sh. 8A, Rev. 12 Figure Al. Type "EL" Auto Train Control Amplifier 5682-G, P A3/4

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