Dc Converter With Microprocessor Control - Tait TB8100 Service Manual

13.8.2

DC Converter with Microprocessor Control

Task 1 —
Check DC Converter
Board, and HVDC
Control and
Microprocessor
Card
234 Power Management Unit Fault Finding
These checks will verify the correct operation of the:
DC converter with microprocessor control
HVDC control and microprocessor card
standby power supply card.
These procedures check the operation of the DC converter when it is under
control of the microprocessor on the HVDC control and microprocessor
card which is plugged into the AC converter board. It is assumed that the
tests described in Section 13.8.1
Note
The AC converter board fitted to a DC PMU is a sub-populated
version of the complete board which is fitted to the AC PMU and
AC and DC PMU. Both types of board work in exactly the same
way for the purpose of testing the DC converter.
Note
Do not connect the standby power supply card at this stage.
In this section voltages are given first for a 12V PMU, followed by voltages
in brackets for a 24V PMU ( ) and a 48V PMU [ ].
1. Connect the DC module to the AC module as shown in
2. Ensure that the DC control card and battery control card are plugged
into the DC converter board, and the PFC control card and HVDC
control and microprocessor card are plugged into the AC converter
board, as shown in
3. Connect the correct DC supply to the input of the DC converter and
measure the voltage at either PA output connector. The output
voltage should be 28VDC. If it is, go to
26.5VDC, go to
4. The HVDC control and microprocessor card is probably faulty
(because the microprocessor adjusts the output voltage to 28VDC).
Replace the card and recheck the voltage. If it is correct, go to
Task 2. If it is not, go to
5. Check that the ribbon cable is undamaged, and is connected securely
with the correct orientation. There is a hole in the PCB beside pin
1 of the connector. If the ribbon cable is not faulty, go to
have been carried out successfully.
Figure 13.8.
Step 4. If it is higher than 28VDC, go to
Step 5.
© Tait Electronics Limited September 2006
Figure
Task 2. If it is approximately
Step
Task
TB8100 Service Manual
13.8.
5.
3.