Sensor / Control Board; Calibrating The Sensor / Control Board (Pcb B3B1Xr04); Testing The Sensor / Control Board (Pcb B3B1Xr04) - Classe Audio Delta Series Service Manual

Sensor / Control Board

Before you begin, perform a detailed visual inspection of the board. Check for missing components, missing
solder or accidental solder bridges (especially under surface-mount ICs). Check direction of all ICs, capacitors,
and diodes, and other visible problems.

Calibrating the Sensor / Control Board (PCB B3B1XR04)

Check all components.
Turn trimpots R3, R4, R15 and R16 CCW to end (minimum).
Short (with a jumper) the two rightmost pins (looking from the top) on connector TO-OP.
Connect a tested PROGRAMMER ADAPTER to connector TO-MAIN-CTR on the control board.
Power-up.
Use local ground on test-point T2 (on the control/sensor board)
Verify local supply voltage: 5.0 Vdc on tab of regulator Q3, and 12Vdc on the left pin of the same
Adjust current zero reference:
o Probe test point T1 and trim R15 CW until voltage on T1 rises to 250mVdc.
o Probe test point T3 and trim R3 CW until voltage on T3 rises to 250mVdc.
Adjust current max reference:
Connect a variac AC power supply to the control board test fixture. Tweak the variac down to minimum, connect
the resistor load to the test fixture and power it on. While monitoring the DC output of the fixture increase the
variac supply until the output reaches 80Vdc across the load (with the load connected). Disconnect the load,
place the control board on the calibration fixture (with mechanical extension to match the new sensor spacing),
and reconnect the load. Power up the test fixture and:
o Probe test point T1 and trim R16 CCW until voltage on T1 rises to 500mVdc.
o Probe test point T3 and trim R4 CCW until voltage on T3 rises to 500mVdc.
Power-off the load and re-adjust current zero reference (re-trim T1 and T3 to 250mVdc). Re-adjust current
max reference (re-trim T1 and T3 to 500mVdc). Repeat if necessary.

Testing the Sensor / Control Board (PCB B3B1XR04)

After calibration (see above) use the same setup to check the following:
Use local ground on test-point T2 (on the control/sensor board)
Verify local supply voltage: 5.0 Vdc on tab of regulator Q3, and 12Vdc on the left pin of the same
Verify the dc-protection reference voltage: 1.84Vdc on test-point T4
Verify the floating output voltage: 1.72Vdc on test-point T5
Verify the output of the optocoupler (pin 3 on Q6). It should be high (5Vdc)
Connect a 10k (code 1002) resistor from ground to the top middle pin of connector TO-OP. The voltage on
test-point T5 should change to 0.92Vdc.
Connect a 10k (code 1002) resistor from the 5V supply to the top middle pin of connector TO-OP. The
voltage at the output of the optocoupler (pin 3 of Q6) should go low (under 0.5Vdc)
CA(P)2100 AMP Service Manual v1.4 inc voltage change info .doc Page 12 of 50