TTI CPX200, Руководство по обслуживанию

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Calibration
Refer to the General section for dismantling instructions and safety precautions. Component
numbers are given for Channel A/Channel B, e.g. VR1/VR101, where VR1 refers to Channel A
and VR101 to Channel B. Channel A is marked as Output 1 on the front panel, Channel B as
Output 2. All adjustments are on the control board unless otherwise stated.
Equipment Required
5½ digit multimeter with better than 0·05% DC Volts accuracy and better than 0·1% DC Amps
accuracy (to 10A); alternatively use a precision shunt for current measurement.
Rheostat or other high power load arrangement to provide up to 5A load at 35V and 10A and 12V.
A small switch, 15k
Ω
resistor and diode.
Voltage Calibration
Connect DMM, set to Volts, across output. Set voltage controls to minimum and current control to
maximum. Switch output ON and check for a reading of 00·00V ± 0·01V on display and DMM.
Set voltage controls to maximum. Adjust VR16/VR116 (maximum output volts) for a reading of
35·30V ± 0·02V on the DMM. Adjust VR2/VR102 (preset volts) until display matches DMM.
Connect rheostat to output and adjust for nominally 4A at maximum output voltage. Reduce
current limit (current control anticlockwise) until output just enters CI mode. Adjust VR8/VR108
(measured volts) until display matches DMM reading.
Current Calibration
Connect DMM, set to 20A range, in series with rheostat set to about 1
Ω
. With output OFF set
voltage controls to maximum and current control to 0·10A. Switch output ON and adjust
VR1/VR101 for 0·10A ± ·01A on DMM.
Set voltage controls to 12V, current control to maximum; supply should be in CI mode. Adjust
VR6/VR106 (maximum output current) for 10·20A ± ·02A on DMM.
Switch output OFF. Adjust VR3/VR103 (preset current) until display matches maximum output set
by VR6/VR106 above.
Increase rheostat resistance until unit enters CV mode. Adjust VR1/VR101 (measured current) on
main board until display matches DMM reading.
Set Power Limit
Switch output OFF, set voltage control to 12·1V, current control to maximum. Switch output ON,
set rheostat so that current is 10·0A (ensure CV mode is maintained). Adjust VR5/VR105 (power
limit) until the UNREG l.e.d. just lights; back off VR5/VR105 until CV is lit and UNREG is off.
Set voltage controls to maximum and check unit enters UNREG mode. Increase rheostat
resistance until unit enters CV mode again; check meter reads between 5A and 6·2A.
Remove load.
OVP Calibration
Set voltage controls to minimum, current control to maximum. Set VR7/VR107 fully anti-
clockwise. Switch output ON. Press OVP button and set front panel OVP control (screwdriver
adjustment) for a display of 20·00V; release OVP button.
Set output voltage to 20·00V and adjust VR7/VR107 (OVP calibrate) slowly anticlockwise until
OVP is tripped (display reads TRIP). Turn output OFF and reset front panel OVP control fully
clockwise.
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