Sm-5886

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WAS CD ~ .~.....__SE_RV_IC_EM_A_NU_AL_58_86_~~ DIGITAL SPEEDOMETER N45li79-02:XX ********* INSTALLATION AND MAINTENANCE CONTENTS I. I. Introduction . • • • • 1 II. General Description 2 III. Installation . • 5 IV. Maintenance . . 5 v. Parts List 10 INTRODUCTION The Digital Speedometer N45 l l 79-02:XX is a solid state device that converts frequency, which is proportional to velocity, into a visual numeric display for use on locomotive and transit car applications. (See Figure 1-1. ) The unit is especially designed to operate in conjunction with WABCO Tachometer Generators N451124-0101 and N451124-0102 or Reluctance Pick-up J738109. Full scale speed ranges of 99 and 199 mph in 1 mph increments and an automatic decimal point giving increments of 0. 1 mph between Oto 10 mph can be supplied. · Accuracy of the unit is ±1% of full range, or 1 digit, whichever is greater. WESTINGHOUSE AIR BRAKE COMPANY SIGNAL & COMMUNICATIONS DIVISION Swissvale Post Office, Pittsburgl:i, Pa. 15218 PRINTED IN U.S.A. A0.70-500-1432.1 An American-Standard Company ~ Jan., 1970 WABCO ~ Figure 1-1. Digital Speedometer II. GENERAL DESCRIPTION The Speedometer housing is constructed of sturdy cast aluminum and is designed to withstand rugged use for wall or panel top mounting. Digital readout is displayed on Nixie tubes as shown in Figure 1-1. The decimal provides automatic dual speed range operation when desired. For maintenance purposes, access to the interior components can be gained by removing the front cover of the housing as shown in Figure 2-1. 5886, p. 2 WABCD ~ Figure 2-1. Digital Speedometer with Interior Components Exposed The complete assembled unit includes a Power Supply Board, Digital Logic Board, Nixie tubes, wheel size adjustment and a seven-pin plug connector. The Power Supply Board as shown in Figure 2-1, attached to the main part of the housing, provides power to operate the Tachometer Generator and Digital Speedometer. The Digital Logic Board attached to the housing cover consists of circuitry to convert electrical pulses (received from the Tachometer or Reluctance Pick-up) into visual numeric display. A slotted adjustment ( located near the plug connector), calibrated in wheel tape sizes, is provided to compensate for wheel wear. All necessary electrical connections to the Speedometer are made through the seven-pin plug connector. 5886, p. 3 WABCO ~ A. Technical Data 1. Power Input: Nominal 72 VDC or 36 VDC battery options available. 2. Signal Input: Output of Tachometer Generator 6 VDC to 18 VDC. ( Frequency proportional to speed ) 3. Power Supply Output: 24 VDC, ±1 VDC@ 0.5A Max. 5 VDC, ±0. 5 VDC @ 0. 25A Max. 200 VDC, ±20 VDC@. Ol5A Max. 4. Velocity Operating Range: Minimum O. 1 mph, Maximum 199 mph. 5. Accuracy: ± 1% of full speed range, or l'Digit, whichever is greater. 6. Operating Temperature Range: -20°C to +70°C (-4°F to +158°F) 7. Connector Test Points: ( Digital Speedometer) a) b) c) d) 8. Reluctance Pick-up Adjustment 15 to 60 mils clearance between gear and Pick-up. 9. Speedometer Housing Dimensions: 6-1/4 inches wide, 10-13/16 inches high, 5-1/8 inches deep. Weight: Approximately 7 lbs. 10. 5886, p. 4 Pin A, Power Supply Common. Pin E, Regulated 24 VDC. Pin D, Battery+. Pin C, Signal input from Tachometer Generator. e) Pin C & F, leads to Pick-up. WABCD ~ III. INSTALLATION Refer to Diagrams, Figures 5-1 and 5-2, for a typical installation of the Speedometer-Tachometer system or Speedometer-Reluctance Pick-up system. I. Complete all wiring connections for whichever combination is used as shown in Figure 5-2. Before proceeding with permanent mounting of Speedometer and Tachometer, an operational check is recommended as follows to ensure that the system is functioning properly. With all wiring connections completed, including power supply, the tenths and ones Nixie tubes ( one tube on each side of the decimal, and the decimal) should glow displaying ( 0. 0). Speedometer-Tachometer Combination Turn the Tachometer Generator shaft by hand at a very slow rate of speed, and if a digital readout is observed, this indicates that the Speedometer is receiving pulses from the Tachometer Generator • .• ' Speedometer-Reluctance Pick-up Combination Refer to Paragraph "B" under "Maintenance" for checking out the Speedometer-Reluctance Pick-up system. The Pick-up is mounted in the gear box and is adjusted for 15 to 60 mils clearance from the gear. 2. For panel top mounting, holes must be drilled in the bottom of the Speedometer housing. Remove the front panel cover and attach the housing to the surface with screws. 3. For wall mounting, mounting brackets as shown in Figure 5-1 are required. (Wall mounting brackets are furnished only when specified. ) After the brackets are mounted properly, attach the Speedometer to the wall surface as shown in Figure 5-1 and secure by inserting screw ( 5) at the bottom of bracket. 4. Wheel size adjustment is made by turning slotted adjustment on side of housing to the proper wheel tape size. IV. MAINTENANCE Periodic maintenance of the Digital Speedometer is not required. If the unit is suspected of not indicating the proper speed, an appropriate speed check should be made. The following procedure can be used as a check against the actual mph ( digital readout) displayed on the Speedometer. I. Clock a measured distance traveled at a constant speed. 2. This distance, divided by the time (in seconds) required to travel it, will result in feet-per-second. Distance Time (sec) = Ft. Per Sec. 5886, p. 5 WABCO ~ 3. Apply the results of Step 2 to the following formula. ( Ft. Per Sec. ) x 3600 Sec. 5280 Ft. = MPH A. Checkout Procedure for Speedometer-Tachometer Combination, or Speedometer-Reluctance Pick-up Combination If the Speedometer system is not functioning properly, the following checkout procedures for either system can be used to localize the fault to a particular unit or the interconnections. 1. Remove the junction box covers and the front panel cover from the Speedometer housing. Visually inspect for damaged components or loose connections. 2. Check for the following power supply voltages with a DC Voltmeter ( Simpson 260 or equiv. ) a. ) Battery voltage 72 VDC, ±12 VDC; or 36 VDC, ±6 VDC. b.) Check the following regulated voltages on the Power Supply Board: ( Terminal numbers and voltages are etched on the P. C. Board) 24 VDC, ± 1 VDC, between Pin 1 ( +) and Pin 6 ( - ) • 200 VDC, ±20 VDC, between Pin 7 (+) and Pin 6 (-). 5 VDC, ±0.5 VDC, between Pin 8 (+) and Pin 6 (-). If these voltages are present and within the given tolerances, proceed to Step 3; if no voltage or improper voltage is present, the Power Supply P. C. Board is faulty. Replace Power Supply Board. NOTE All given power supply voltages must be present before the system will operate properly. 3. If a Reluctance Pick-up is used in conjunction with the Speedometer, proceed to Paragraph "B". If a Tachometer Generator is used, continue with Step 4. 4. Remove the Tachometer Generator from the journal box so that the shaft can be turned by hand. While turning the Tachometer shaft very slowly, check the voltage on the Digital Logic Board between terminal 7 (positive) and terminal 1 (common) with the DC Voltmeter. If the Voltmeter indicates a voltage fluctuation between 6 VDC and 18 VDC, the Tachometer is functioning properly and the faulty condition is in the Digital Logic Board circuitry. 5886, p. 6 WABCD ~ NOTE The Tachometer shaft must be turned very slowly. If it is turned too fast, the DC Voltmeter will average the fluctuations and a steady DC voltage will be indicated on the Voltmeter, rather than the desired voltage fluctuation. If no fluctuations are observed on the Voltmeter, either the Tachometer has failed or cable continuity between the Speedometer and Tachometer has been interrupted. 5. Remove the plug connector from the Tachometer Generator,and with a DC Voltmeter check for 24 VDC, ± 1 VDC, between pins E (positive) and A (Common) at the Tachometer cable connector. If 24 VDC is not present, leads from the Speedometer are open. Check and ,correct the faulty condition. If 24 VDC is present, check for continuity and shorts in the line between terminal C ( signal output) at the Tachometer plug connector and terminal 7 on the Digital Logic Board. If all lines check out properly, this indicates a faulty Tachometer Generator. Refer to Service Manual 5856 for further information on the Tachometer Generator. Alternatively, in the case of a faulty Speedometer, the following procedure in Paragraph "C" can be used to determine whether the Power Supply Board or Digital Logic Board is defective. B. Checkout Procedure for Reluctance Pick-up The following checkout procedure is recommended to determine if the Reluctance Pick-up is functioning properly. Refer to Figure 5-2 when following this procedure. I. Remove the plug connector from the Speedometer and measure the resistance between Pins "C" and "F" ( leading to the Pick-up) with a DC Voltmeter. If approximately 200 ohms is indicated on the meter scale, the Pickup is operable, which indicates the faulty condition exists in the Digital Logic Board circuitry. If the meter does not indicate 200 ohms, the Pick-up may be faulty, continuity in the leads to the Pick-up may be interrupted, or the Pick-up is not positioned close enough to the gear. 5886, p. 7 WABCO ~ 2. Remove the cable connector at the Pick-up and attach the DC Voltmeter leads directly to the two terminals leading to the Pick-up. If the proper ohm reading ( 200 ohms ) is obtained at these points, then faulty wiring exists somewhere in the line between the Pick-up and the Speedometer. If the proper reading is not observed, then the Pick-up is faulty. Replace the Reluctance Pick-up. C. Checkout Procedure for Speedometer ( Figure 4-1 ) Test Equipment Requirements 1. Audio Signal Generator (Ungrounded), for generating 4 volts RMS. 2. DC Voltmeter (Simpson 260 or equiv.). 3. Power Supply: 72 VDC (±12 VDC ), or 36 VDC (±6 VDC ). 4. P.lug connector for Speedometer. Same as item 2 listed in parts list. 5. Terminal strip. SPEEDOMETER HOUSING COVER SPEEDOMETER MAIN HOUSING PLUG CONNECTOR DIGITAL LOGIC BOARD POWER SUPPLY BOARD TEST POINTS. 1 7 8 6 / _ TERMINAL STRIP + BATTERY D r -, I D I COMMON '1 A A + 72 VDC OR 36 VDC POWER SUPPLY SIGNAL INPUT + D.C. VOLTMETER SIGNAL GENERATOR NOTE: USE PROPER POWER SUPPLY ( 72 VDC OR 36 VDC ) FOR SPEEDOMETER UNDER TEST Figure 4-1. Digital Speedometer Test Setup 5886, p. 8 WAEICD ~ The following is a Speedometer component checkout procedure to determine whether the Power Supply Board or Digital Logic Board are functioning properly. 1. Connect the test setup procedure as shown in Figure 4-1. Remove front cover from the Speedometer housing, but do not disconnect any internal wiring. CAUTION Use proper power supply ( 72 VDC or 36 VDC ) for Speedometer under test to prevent damage to power supply board components. A Speedometer using a 72 VDC power supply can be identified by the two power resistors located at the bottom of the housing. 2. With the power supply connected, check the following regulated voltages with a DC Voltmeter. a. ) 24 VDC, ± 1 VDC, between Pin 1 ( +) and Pin 6 ( - ) . b.) 200 VDC, ±20 VDC, between Pin 7 (+) and Pin 6 (-). c.) 5 VDC, ±0.5 VDC, between Pin 8 (+) and Pin 6 (-). If any one of the given voltage readings are not present, the power supply is faulty. Replace Power Supply Board. All given voltages must be within the specified tolerances for proper operation of the Speedometer. NOTE With the power supply working properly and connected to the Speedometer, the tenths and ones tubes on each side of- the decimal, and the decimal should glow displaying ( 0. 0 ) . 3. Set the Signal Generator to deliver 4 volts rms at a frequency of 2 KHz. Set the wheel tape size adjustment to 126 inches. The Speedometer digital readout should indicate 99 mph. The input for a 99 mph full scale range is 25. 2 Hz for each mph. ( 25. 2 Hz x 99 mph= 2 KHz. ) Note: 25. 2 Hz/mph is true at a wheel tape size adjustment of 126 inches. For full scale range of 199 mph, set the Signal Generator at 5 KHz. (25. 2 x 199 = 5 KHz.) If no readout is displayed, or if the unit displays an improper readout, this indicates faulty circuitry in the Digital Logic Board. A Speedometer unit which is found to be faulty should be returned to WABCO Signal & Communications Division for repair and adjustment. 5886, p. 9 WABCC ~ V. PARTS LIST A. Mounting Bracket The following parts list for the Speedometer housing wall mounting bracket assembly is keyed to Figure 5-1. ITEM NO. PART NO. DESCRIPTION 1 2 3 4 5 6 M451180-0303 M451180-0301 M45 l l 80-0302 J52562 J51668 J47733 Mounting Bracket Clip Fastening Plate Screw, 10-32 x 5/16 Rd. s. TP Screw, 10-32 x 1/2 Rd. S. TP Washer, 10 LK. S. TP SPEEDOMETER HOUSING i--- 4-1/4 - - - 2-1/8 0 NOTE: SPEEDOMETER HOUSING DIMENSIONS: 7 6-1/4" WIDE, 10-13/16" HIGH, 5-1/8" DEEP. HOLES FOR HOUSING ARE PRE-DRILLED AT FACTORY. 00 0 0 Figure 5-1. Speedometer Mounting Bracket Parts Locations Diagram 5886, p. 10 WABCO ~ B. Digital Speedometer The following is a parts list for both systems keyed to Figure 5-2. REF. NO. DESCRIPTION PART NUMBER 1* Digital Speedometer Power Supply Board Digital Logic Board Plug Connector Cable Grip Connector Junction Box Cable Grip Connector Tachometer Generator: Single Channel Dual Channel Reluctance Pick-up Cable Connector ( type of connector varies with application ) N45 l l 79-02XX N451055-1901 N451055-2001 J706312 J712003 N285017 N311301 . . 2 * 3* 4* 5 * 6 7 8 ,. N451124-0101 N451124-0102 J738109 * Items used with Tachometer or Reluctance Pick-up. SPEEDOMETER MOUNTED IN CAB !DQ1.l9J! 3 CONDUIT WIRING FOR RELUCTANCE PICK-UP 72 voe OR 36 voe -BAIT +BATT 4 CONDUIT JUNCTION BOX Al 2 0 0 0 0 PLUG CONNECTOR 5 CABLE GRIP CONNECTOR ~--r--~, I WIRING FOR TACHOMETER GENERATOR • CABLE 72 A I 0 0 FLEXIBLE C A ~I L E CONtCTOR Al A RELUCTANCE PICK-UP voe OR 36 voe -BAIT + BATT C D D A o+----+-0-.1----~F><>-+----+-O-+-COMMON o-+-----+-<>-,1------.1-0-+-----+o-+-- REGULATED I 24 'GEARBOX voe u ; - - - - - ; - - u - ; , - - - - - - , t - O - t - - - - - - t - U - t - - SIGNAL INPUT Figure 5-2. Digital Speedometer Equipment Parts Locations Diagram 5886, p. 11