Replacement Parts; Adjustment And Calibration - HP 59501A Operating And Service Manual

5-17 REPLACEMENT PARTS
5-18 Section VI of this manual contains a list of re¬
placeable parts. If the part to be replaced does not have
a standard manufacturer's part number, it is a special
part number and must be obtained directly from Hewlett-
Packard.
5-19 ADJUSTMENT AND CALIBRATION
5-20 The 59501A is factory calibrated to operate
properly regardless of the mode selected (unipolar or
bipolar). The calibration procedures, described in para¬
graphs 5-21 through 5-26, may be required afttjr perform¬
ing the checkout procedures, troubleshooting, or repair
and replacement. Once the unit is calibrated, the front
panel controls may be adjusted as required for unipolar
or bipolar operation (paragraphs 5-27 through 5-30).
5-21 Calibration
5-22 The calibration procedures must be performed
it! the order in which they are presented in the following
paragraphs.
5-23 Test Setup.
a. Remove the bottom cover to gain access to
the potentiometers on the A1 board (see Figure 7- ).
b. Connect oscilloscope to the A1 and A2 output
terminals on rear of 59501 A. Connect scope common to the
A1 terminal. Set Time/Div. to Imsec/div and Volt/Div. to
1 mV/cm.
c. Check that the address switches on the rear
of the 59501 A are set to ^2
d. Connect the 59501A to an HP-IB controller.
e. Apply power to 59501A and controller. Allow
a 30-minute warmup.
5-24 Unipolar Mode — Zero Programming Accuracy.
To adjust the zero programming accuracy in the high and low
output ranges, proceed as follows;
a. Set mode switch on rear of 59501A to
UNIPOLAR.
b. Program 59501A to "Listen" and alternately
send data words "1000" (zero low range) and "2000" (zero
high range).
c. Adjust potentiometer A1 R61 (unipolar zero
balance) for a straight line as indicated on the scope.
d. Remove scope and connect a DVM between
the A1 and A2 output terminals. Connect DVM common
to A1.
G. Send data word "2000" to the 59501 A.
f. Adjust front panel ZERO ADJUST for a
reading of OV ±1 mV on DVM.
5-25 Unipolar Mode — Full Scale Programming
Accuracy. To adjust the full scale programming accuracy
in the high and low ranges, proceed as follows;
a. Send data word "2999" (high range full scale)
to the 59501 A.
b. Adjust D/A FULL SCALE ADJUST for a
reading of +9.99V
±
1 mV on DVM.
c. Send data word "1999" (low range full scale)
to the 59501 A.
d. Adjust potentiometer A1 R49 (low range gain)
for a reading of +0.999V ± O.lmV on DVM.
e. Check the zero programming accuracy (para¬
graph 5-24 steps a through e) and the full scale program¬
ming accuracy (steps a through d above) and repeat both
procedures if required.
5-26
Bipolar
Mode -
Zero
Programming
Accuracy.
Use
the same test setup as described in paragraph 5-23.
a. Perform steps 5-243 through 5-24e.
b. Set mode switch on rear of 59501A to
BIPOLAR.
c. Program 59501A to "Listen" and alternately
send data words "1500" (OV, low range) and "2500"
(OV, high range).
d. Adjust potentiometer A1 R26 (bipolar zero
balance) for a straight line as indicated on the scope.
5-27 Front Panel Adjustments
5-28 After the- unit is calibrated, the front panel
controls are adjusted for unipolar or bipolar operation.
Note that the following procedures adjust the output of
the 59501A when it is to be used as a DAC. If the 59501A
is to be used as a power supply programmer, follow the
calibration procedures provided in Section III (paragraphs
3-53 through 3-68.
5-29 Unipolar Mode. Use the same test setup as
paragraph 5-23 except connect a DVM between the A1 and
A2 output terminals. Connect the DVM common to the
A2 terminal.
a. Set mode switch to UNIPOLAR.
b. Program 59501A to "Listen". Send data word
"2000" (high range zero) and adjust front pane! ZERO
ADJUST for a reading of OV ±0,1 mV on DVM.
c. Send data word "2999" (high range full scale)
and adjust front pane! D/A FULL SCALE ADJUST for a
reading of +9.99V ± 1 mV on DVM.
5-30 Bipolar Mode. Use same test setup as above,
a. Set mode switch to BIPOLAR.
b. Send data word "2000" and adjust ZERO
ADJUST for a reading of —lOV ±1mV on DVM.
c. Send data word "2999" and adjust D/A FULL
SCALE ADJUST for a reading of +9.98V ±1 mV on DVM.
d. Repeat steps b and c.
5-6