B&K Precision 1762 - Manual - Manual (Page 44)

44
MAINTENANCE
3. Set the Right V/A switch to the A position.
4. Connect the external multimeter across the “A” SUPPLY
output terminals to read the output current (so that the meter
causes a short circuit across the terminals) and adjust the “A”
CURRENT control so that 2.00 amps is read on the “A”/4-
6.5V LED Display.
5. Adjust R163 (“A” SUPPLY A METER ADJ) so that the
multimeter also reads 2.00 amps.
II. 4-6.5V SUPPLY AND 4-6.5V METERING
ADJUSTMENTS
5. Set the 0-30V/4-6.5V switch to the 4-6.5V position and the
Right V/A switch to the V position.
6. Connect an accurate (±0.1%) external 4-1/2 digit multimeter
across the output terminals of the 4-6.5V SUPPLY to read
output voltage and adjust the 4-6.5V front panel voltage level
control to minimum (4V, fully counterclockwise).
7. Adjust R134 (4-6.5V 3.9V REF) located on the main board
for a reading of 3.90 volts on the external multimeter.
8. Adjust R133 (4-6.5V V METER ADJ) located on the main
board so that the “A”/4-6.5V LED Display reads 3.90 volts.
9. Set the Right V/A switch to the A position.
10. Turn R122 (4-6.5V A METER & A LIMIT ADJ) and
R159 (4-6.5V 6.8V REF) located on the main board fully
clockwise.
1.
Connect a 1 Ω load (rated at 30W or more) and the
multimeter in series across the output terminals of the 4-
6.5V SUPPLY to read the output current.
2. Adjust the 4-6.5V voltage level control to obtain an
output of 5.30 amps (read on the multimeter).
3. Adjust R122 (4-6.5V A METER & A LIMIT ADJ) so
that the “A”/4-6.5V LED Display also reads 5.30 amps.
4. Slowly Adjust R159 (4-6.5V 6.8V REF)
counterclockwise until the OVER indicator on the
1760 Front Panel just lights.
III. “B” SUPPLY AND METERING ADJUSTMENTS
1. Connect an accurate (±0.1%) external 4-1/2 digit
multimeter to measure the DC voltage at the output
terminals of the “B” SUPPLY.
2. Disengage the INDEP/TRACK mode switch (out) so
that the power supply is in the INDEPendent operating
mode.
3. Set the “B” VOLTAGE controls (both Coarse and
Fine) to maximum (fully clockwise).
4. Adjust R10 (“B” SUPPLY +5V REF) on the main
board for as close to 30.70 volts (on the multimeter) as
possible.
5. Set the Left V/A switch to the V position.
6. Adjust R304 (“B” SUPPLY V METER ADJ) on the
“B” panel board (located on the left side of the supply
behind the “B” LED Display) for a reading of 30.7
volts on the “B” LED Display.