105401-0503 ZEXEL 9 420 612 090 BOSCH GOVERNOR 9420612090 1054010503 223203290a

Test Points (Voltages And Waveforms)
dc Voltages Conditions: 1. dc input voltage applied to POWER connector as shown.2. CALIBRATION CHECK/OPERATE switch in the OPERATE position.3. Neither transducer connected to indicator.4. TPI is reference for all voltages.Equipment Required: 6V3030 Digital Multimeterdc Input Voltages Waveforms Conditions: 1. dc power input voltage of 25 1 Volts.2. CALIBRATION CHECK/OPERATE switch in the CHECK position (can be held in CHECK position with tape).3. Neither transducer connected to indicator.4. TPI is reference for all waveforms.Equipment Required: dc oscilloscope (dual channel preferred). Waveform Time Relationships
VOLTAGES MAY VARY 10%, PULSE DURATIONS BY 20% EXCEPT 2.66 ms WHICH IS BASED ON A 12.000 kHz OSCILLATOR FREQ. (1C202). SIGNAL SOURCE IS INTERNAL CALIBRATOR. ALL TEST POINTS REFERENCED TO TP1.Waveform Time Relationships (enlarged scale)
VOLTAGES MAY VARY 10%, PULSE DURATIONS BY 20% EXCEPT 83.3 ?s AND 2.66 ms WHICH ARE EXACT BASED ON A 12.000 kHZ OSCILLATOR. (1C202) SIGNAL SOURCE IS INTERNAL CALIBRATOR. ALL TEST POINTS REFERENCED TO TP1.Disassembly Procedure
1 Remove six screws (1) from front panel (2), and remove panel (2) from case (3). Remove four screws (4) from the PC board, and also remove the locknuts from the two front panel switches (5) and (6). Carefully lift front panel (2) from PC (printed circuit) board (7).Calibration Procedure
To make sure the 6V3100 Timing Indicator Group (1) has good accuracy, check its calibration at a minimum of every six months. Also, the timing indicator will need calibration if: A. It does not show 2000 30 R/MIN at (A) and 32.0 .2 DEG at (B), when the CALIBRATION CHECK-OPERATE Switch (C) is in the CALIBRATION CHECK position. With no input signal at (D) or (E), the reading at R/MIN location (A) must show three zeros (000). If four zeros (0000) show, it is an indication of a possible need for calibration of the unit. This error only is not reason enough to do a complete calibration procedure. It is also not necessary to do a complete calibration procedure if the reading at the DEG location (B) has a decimal point as shown, (00.0) in addition to the three zeros.B. Reading is different than (000) at either location (A) or (B).All calibrations can be done with the use of a small screwdriver, a frequency counter and