AnsaldoSTS F-42, Установка, эксплуатация и обслуживание

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PARTS LIST
SM 5924, Rev. 1, June 2009 4-1
4 MAINTENANCE AND TROUBLESHOOTING
4.1 General
Maintenance consists of an occasional check of the output voltage. If no output voltage is
indicated, check the input circuit for a blown fuse (Fl, 10 amp slow-blow). To calibrate the
output voltage, refer to Section 3.3. If improper output voltage or no output voltage is obtainable,
troubleshoot the converter by following the steps in the Sections that follow. The schematic is
shown in Figure 4–1. F-42 DC/DC Converter Schematic Diagram is shown in Figure 4–1.
4.2 Converter Regulator Section
1. Disconnect terminal TP7-1 located between transistor Q4 emitter and capacitor C3. This
separates the pre-regulator from the converter output section.
2. Place a DC voltmeter (0-50V) across the terminals of C3 (tie point TP6-4 and collector of
Q5) and a 0-100 VDC variable power supply (approximately 1 amp capacity) across the +
and - input terminals of connector P4.
3. Slowly increase the voltage from OV and observe that the output voltage is rising with the
input voltage. At approximately 38V input, adjust the control pot R15 of CB1 for a 32V
output.
NOTE
If a 32V output cannot be obtained, the cause may be due to faulty
printed circuit boards CB1 or CB3 or components mounted on the
chassis. Transistors Q1, Q2, and Q3, should be checked for short
circuits. See checkout procedures for printed circuit boards CB1
and CB3 in Sections 4.4 and 4.5.
If the requirements in Steps 1 to 3 are met, proceed with Step 4.
4. Readjust the voltage from OV, as indicated in Step 3, and observe that the output voltage
does not rise above 32V with the input range from 0V to 45V. The input current should be
approximately 0.1 amps at this point.
5. Gradually increase the input voltage to +80V and observe that the output voltage remains at
32V. The input current should be approximately 0.1 amps at this point. The current will vary
slightly with component variations.