Transcript
SERVICE MANUAL
5685
CODE MODULATOR UNIT FOR UNION TYPE "EL" CODED CAB SIGNAL EQUIPMENT
..
Pc. UN339647-D66026-Sh. 9
************************* TABLE OF CONTENTS Page I. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II. Assembly and Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . m. Detail Parts Specification . . . . • . • • • • • . • • • • • . . • • • . • • • • IV. Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... Schematic Circuit Plan •..•••....•.••.••••••••••• Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 1 2 2
4 5
I. GENERAL The purpose of the code modulator is to produce 180-code operation of the master relay of a standard code cab signal equipment when the receiver is energized by steady (uncoded) a-c track current. This permits operation of a twoindication code cab signal equipment in non-code cab signal territory. The modulator consists essentially of a transistor oscillator tuned for 184. 5 eye les per minute with the secondary of the tuned transformer connected through a diode and a resistor across the terminals of the track receiver. The effect is to short circuit the track receiver on every other half-cycle of the 184. 5 c. p. m. frequency, thus "chopping up" or modulating the steady energy in the receiver to produce coded energy. All the circuit components are mounted on a separate base plate attached to the bottom of the case and they are protected from dirt and moisture by the cover. Attached to the case are the handle for withdrawing and carrying the unit, the guide bars which engage those on the equipment box shelf for proper alignment of the plug connectors, and the name plate. Each unit bears its own serial number stencilled on the name plate. Also mounted on the front of the case is a test jack for measuring the transistor collector current. II. ASSEMBLY AND WIRING If it should become necessary to dismantle the code modulator unit for repair, the base plate carrying the components can be removed from the case without disconnecting any wiring by following the procedure described in the next paragraph. April, 1959 A-2/84-100~2657-2 PRINTED IN USA
UNION SWITCH & SIGNAL DIVISION AMERICAN STANDARD INC./ SWISSVALE, PA 15218
1
SERVICE MANUAL
5685
CODE MODULATOR UNIT FOR UNION TYPE "EL" CODED CAB SIGNAL EQUIPMENT Pc. UN339647-D66026-Sh. 9
************************* TABLE OF CONTENTS Page I. II. III. IV.
I.
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assembly and Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Detail Parts Specification • . • . • . • • • • • • • • • • • . . • . • . . ••• Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Schematic Circuit Plan ....••..•••.....••••.•.••• Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 1 2 2 4
5
GENERAL
The purpose of the code modulator is to produce 180-code operation of the master relay of a standard code cab signal equipment when the receiver is energized by steady (uncoded) a-c track current. This permits operation of a twoindication code cab signal equipment in non-code cab signal territory. The modulator consists essentially of a transistor oscillator tuned for 184. 5 cycles per minute with the secondary of the tuned transformer connected through a diode and a resistor across the terminals of the track receiver. The effect is to short circuit the track receiver on every other half-cycle of the 184. 5 c. p. m. frequency, thus "chopping up" or modulating the steady energy in the receiver to produce coded energy. All the circuit components are mounted on a separate base plate attached to the bottom of the case and they are protected from dirt and moisture by the cover. Attached to the case are the handle for withdrawing and carrying the unit, the _ guide bars which engage those on the equipment box shelf for proper alignment of the plug connectors, and the name plate. Each unit bears its own serial number stencilled on the name plate. Also mounted on the front of the case is a test jack for measuring the transistor collector current. II. ASSEMBLY AND WIRING If it should become necessary to dismantle the code modulator unit for re-
pair, the base plate carrying the components can be removed from the case without disconnecting any wiring by following the procedure described in the next paragraph. A~_ril_,__ 1959 A-2/84-100~2657-2 PRINTED IN USA
UNION SWITCH & SIGNAL DIVISION AMERICAN STANDARD INC./ SWISSVALE, PA 15218
u. s. & s.
- 2-
5685
Remove the two screws holding the test jack to the front of the case. Remove the four screws holding the plug connector to the case and rotate the plug connector into a position from which it can be pushed through the rectangular hole to the inside of the case. After removing the four screws which hold the base plate to the bottom of the case, the entire assembly can be removed from the case. The plug connector has been 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. If it should become necessary to replace a plug connector by a new one, new holes (#52 drill size) for the dowels should be drilled in the plug connector and the case in a new location. An equipment box shelf can be used as a fixture for correctly locating the plug connector on the case. All wires except coil leads are #18 B. & S. gauge flexible stranded wire with extruded plastic insulation. The leads which are connected to the plug connector should be left sufficiently long to facilitate the operation of pushing the plug connector through the rectangular hole. ill.
DETAIL PARTS SPECIFICATION
1. Transformer. The resistance of the primary should be 98 ohms ±10%, that of the secondary, 210 ohms ±10% and that of the tertiary, 2000 ohms ±10%.
2. Resistors and Capacitor. Measured values of resistance should be within 10% of the value indicated on the schematic circuit, Figure 2. The measured value of capacitance of the capacitor should be between 4. 8 and 7. 2 mfd. IV. MAINTENANCE 1. Mechanical Inspection. Carefully examine every part of the assembly to make certain that there are no improperly soldered joints, untightened screws and nuts or damaged insulation and that lead wires are so arranged and cabled that they will not be pinched when the cover is applied to the case. 2. Electrical Inspection. The code modulator 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. For testing, the code modulator should be plugged into an equipment box shelf to which is connected the receiver circuit and the d-c supply as shown in Figure 1. Also in place on this shelf should be an amplifier, a master relay, a decoding transformer unit, a 180-code decoding unit and a PN-59 decoding relay. Connect a standard phone plug to the terminals of a 10 ma. or 15 ma. d-c milliammeter with the "+" terminal of the meter connected to the tip of the plug. Insert the phone plug into the test jack on the modulator unit. The plug should freely enter the jack and snap into place with no tendency to jar out. Set the d-c supply voltage at exactly 32 volts and adjust the track current to 0. 5 amps. The master relay should operate at 180 code rate and the decoding relay should pick up. Using a stop watch count the numper of master relay operations for one minute. (Movement of the master relay armature from one side to the other and back constitutes one operation). The number of master relay
5685
- 3-
U.S. & S.
t-------------------------------------+32 11---------------------------------------32
TYPE EL EQUIPMENT BOX SHELF'
T1 TC
,,
110 VOLTS ,
eo
CYCLES
TC
T1
STANDARD RECEIVER AT NORMAL LOCATION -...... TRACK TRANSFORMER
Wlilwi.r---------------------'
~r.AA---------------
(mllfOllil>'?f'._______
I OHM
RAILS
•' ai"
'------------~Ai-------------Fig. 1 . . . Circuit for Operating Test of Code Modulator.
operations in one minute should be between 182 and 187. If the rate of operation is not within these limits, the oscillator transformer must be re-tuned. As this . tuning operation requires the use of equipment not usually available on a railroad, any code modulator which requires re-tuning should be returned to the Union Switch & Signal Division of Westinghouse Air Brake Co., Swissvale, Pa. If the master relay is operating at the correct rate, measure the decoding relay current at the 180-code decoding unit in the manner described in Instruction Pamphlet U-5684-A. This current should be not less than 55 ma. {
If the master relay does not operate at all, observe the current reading on the milliammeter connected to the phone plug inserted in the test jack. This current should be pulsating at the code rate with an average value of about one milliampere. A current reading of less than this value, or steady current, indicates a defective component in the oscillator circuit. If the correct current reading is obtained and the master relay still does not · operate, disconnect the receiver leads from the Tl and TC terminals on the shelf terminal board and in their place connect a 2. 5-volt d. c. voltmeter having a resistance of at least 50, 000 ohms, with the"+" terminal of the meter connected to the TC terminal. (A Simpson Model 260 Volt-Ohmmeter is satisfactory for this purpose). A voltage pulsating at the code rate and averaging about one volt should be read on this meter. Any voltage reading differing materially from this indicates a defect in the output circuit.
u. s. & s.
5685
- 4-
,----------------------, 113 IOOOW
TEST JACK
c
E TC
6.0
MFD. Ill 100"'
Ill 1500°'
Tl
' ))'
ISi
c
L_ ___ - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _J Fig. 2 • . . Schematic Circuit Plan of Code Modulator
Whenever it is found necessary to replace a transistor or a diode, great care must be exercised when soldering the leads to the terminal strip. These leads must be handled carefully in order to prevent breakage at the point INhere they emerge from the unit. Also, in order to prevent overheating the unit when soldering the leads, the lead wires should be held by a pair of pliers at a point between the unit and the soldered joint.
\
u. s. & s.
- 5-
5685
TOP OF ..DNES SOCKET (VIEWED FROM INSIDE OF CASE)
~·---9.2-
LOWER TERMINAL STRIP
6
MFD.
TEST JACK Fig. 3 ... Wiring Diagram of Code Modulator
UNION SWITCH & SIGNAL DIVISION HEADQUARTERS
American Standard Inc. Swissvale, PA 15218 (412) 273-4000
·EASTERN OFFICES
WESTERN OFFICES
PHILADELPHIA OFFICE
2 Penn Center Plaza Room 1630 Philadelphia, PA 19102
(215) 568-8032
ST. PAUL OFFICE
402 McColl Bldg. 5th & Jackson St. Paul, MN 55101
(612) 222-7562
JACKSONVILLE OFFICE
P.O. Box 8609 Jacksonville, FL 32211
(904) 724-2607
903 Sneath Lane Suite 2300 San Bruno, CA 94066
(415) 588-6788 Or 6789
NEW YORK OFFICE
40 W. 40th. St. Room 1105 New York, NY 10018
(212) 840-5438 840-5439
SAN FRANCISCO OFFICE ST. LOUIS OFFICE
500 Northwest Plaza Suite 820 St. Ann, MO 63074
(314) 291-7400
CANADIAN OFFICE MONTREAL OFFICE
1155 Dorchester Blvd.,W.Suite 1003 Mont.,PQ Can.,H3B 2J2
(514) 866-3677
REGIONAL OFFICES ATLANTA
(404) 458-5916
ROANOKE OFFICE
(703) 989-8400
HUNTINGTON OFFICE
(304) 736-2629
CHICAGO OFFICE
(312) 759-3577
OMAHA OFFFICE
(402) 334-1516
MAIL ALL ORDERS TO: ORDER ENTRY DEPARTMENT UNION SWITCH & SIGNAL DIVISION AMERICAN ST AND ARD INC. SWISSVALE PA 15218
t
•
I
UNION SWITCH &SIGNAL DIVISION HEADQUARTERS
American Standard Inc. Swissvale, PA 15218 (412) 273-4000
EASTERN OFFICES
WESTERN OFFICES
PHILADELPHIA OFFICE
2 Penn Center Plaza Room 1630 Philadelphia, PA 19102
(215) 568-8032
ST. PAUL OFFICE
JACKSONVILLE OFFICE
P.O. Box 8609 Jacksonville, FL 32211
(904) 724-2607
NEW YORK OFFICE
40 W. 40th. St. Room 1105 New York, NY 10018
(212) 840-5438 840-5439
402 McColl Bldg. 5th & Jackson St. Paul, MN 55101
(612) 222-7562
SAN FRANCISCO OFFICE
903 Sneath Lane Suite 2300 San Bruno, CA 94066
(415) 588-6788 Or 6789
ST. LOUIS OFFICE
500 Northwest Plaza Suite 820 St. Ann. MO 63074
(314) 291-7400
CANADIAN OFFICE MONTREAL OFFICE
1155 Dorchester Blvd.,W.Suite 1003 Mont.,PQ Can.,H3B 2J2
(514) 866-3677
REGIONAL OFFICES ATLANTA
(404) 458-5916
ROANOKE OFFICE
(703) 989-8400
HUNTINGTON OFFICE
(304) 736-2629
CHICAGO OFFICE
(312) 759-3577
OMAHA OFFFICE
(402) 334-1516
MAIL ALL ORDERS TO: ORDER ENTRY DEPARTMENT UNION SWITCH & SIGNAL DIVISION AMERICAN ST AND ARD INC. SWISSVALE PA 15218
l
)
\-"
