GW Instek GPS-x303 Series - Manual (Page 14)

MULTI-OUTPUT POWER SUPPLY
USER MANUAL
22
K. Set output off by adjusting the trimmer potentiometer (VR903 CH2,
VR703 CH1) so that the CH1(CH2) meter also reads rating amps
(invalid for GPS-2303).
(2) Series Tracking Adjustment
A. Set the supply to Tracking series mode by engaging the left Tracking
switch and releasing the right tracking switch.
B. Set the CH2 CURRENT control to midrange and set the CH1 supply
voltage controls to minimum (fully counterclockwise).
C. Connect the multimeter to the CH1 SUPPLY outputs and measure the
voltage.
D. Disconnect the multimeter from the CH1 supply outputs and connect it
across the CH2 supply outputs.
E. Adjust trimmer potentiometer VR306 on the circuit board (located on the
right side of the supply) to obtain the exact same reading for the CH2
supply output as was preset at the CH1 supply output (e.g., if the
minimum CH1 supply output voltage is –10.00mV adjust VR306 to
obtain an output voltage as close to -10.00mV at the CH2 supply as
possible).
F. Set the CH2 CURRENT control to midrange and set the CH1 supply
voltage controls to maximum (fully clockwise).
G. Connect the multimeter to the CH1 supply outputs and measure the
voltage.
H. Disconnect the multimeter from the CH1 supply outputs and connect it
across the CH2 supply outputs.
I. Set output on by adjusting VR501 (located at the left of the lower front
panel circuit board, VOLTAGE/CURRENT CONTROL potentiometer
board) until the voltage read from the multimeter is the same as it was
across the CH1 output terminals. Return the multimeter to the CH1
output terminals and verify that the output voltage is identical. If not,
repeat this step.
J. Set output off by adjusting VR804 (located at the left of the lower front
panel circuit board, VOLTAGE/CURRENT CONTROL potentiometer
board) until the voltage read from the multimeter is the same as it was
MULTI-OUTPUT POWER SUPPLY
USER MANUAL
23
across the CH1 output terminals. Return the multimeter to the CH1
output terminals and verify that the output voltage is identical. If not,
repeat this step (invalid for GPS-2303).
(3) Parallel Tracking Adjustment
A. Disengage both Tracking mode switches (both switches out) so that the
power supply is in the independent operating mode.
B. Set the CH1 supply VOLTAGE and CURRENT controls to minimum
(fully counterclockwise).
C. Connect the multimeter across the CH1 supply output terminals and
measure the output current.
D. Set the CH1 supply VOLTAGE control to midrange and adjust the
CURRENT control to obtain an output current of rating amps (read on
the multimeter). Do not change the CURRENT control setting after this
step.
E. Engaged both Tracking mode switches (both switches in), so that the
power supply is in the parallel operating mode.
F. Set the CH2 supply CURRENT control to maximum (fully clockwise)
and set the VOLTAGE control to midrange.
G. Set output on by adjusting the trimmer potentiometer VR502 on the
circuit board (located on the right side of the supply) to obtain an output
current of double rating amps on the multimeter.
(4) CH3 Supply Adjustment
A. Connect the multimeter across the output terminals of the CH3 supply to
read output voltage and adjust the VR403 to obtain reading of
2.2~5.2V(GPS-4302/4303), 3~6V(GPS-4251) and fixed 5V(GPS-3303)
on the multimeter.
B. Set the supply VOLTAGE control to maximum (fully clockwise), set
output off by adjusting trimmer potentiometer VR203 on the CH3
voltage indicator circuit board (located on the meter or A/D converter
board) for a reading of rate voltage on the CH3 (invalid for GPS-3303).
C. Turn VR401 on the main master circuit board (located on the right side
of the supply) fully counterclockwise.