14 Verification
CV Load Effect
This test measures the change in output voltage resulting from a change in output current from full load to no load.
a.
Turn off the supply and connect the output as shown in Figure 2-1 with the DVM connected between the +S and -S
terminals.
b.
Turn on the supply and program the current to the maximum programmable value and the voltage to the full-scale value
(see Table 2-3).
c.
Adjust the load for the full-scale current (see Table 2-3) as indicated on the front panel display. The CV annunciator on
the front panel must be on. If it is not, adjust the load so that the output current drops slightly.
d.
Record the output voltage reading on the DVM connected to +S and -S.
e.
Open the load and again record the DVM voltage reading.
The difference between the DVM readings in steps (d) and (e) is the load effect voltage, and should not exceed the value
listed in the Performance Test Record Form for the appropriate model under CV LOAD EFFECT.
CV Source Effect
This test measures the change in output voltage that results from a change in AC line voltage from the minimum to
maximum value within the line voltage specifications.
a.
Turn off the supply and connect the AC power line through a variable voltage transformer.
b.
Connect the output as shown in Figure 2-1 with the DVM connected between the +S and the -S terminals. Set the
transformer to nominal line voltage.
c.
Turn on the supply and program the current to the maximum programmable value and the output voltage to the
full-scale value (see Table 2-3).
d.
Adjust the load for the full-scale current value (see Table 2-3) as indicated on the front panel display. The CV
annunciator on the front panel must be on. If it is not, adjust the load so that the output current drops slightly.
e.
Adjust the transformer to 13% below the nominal line voltage (e.g., l04.4 Vac for a 120 Vac nominal line voltage
input).
f.
Record the output voltage reading on the DVM.
g.
Adjust the transformer to 6% above the nominal line voltage (e.g., 127.2 Vac for 120 Vac nominal line voltage input).
h.
Record the output voltage reading on the DVM.
The difference between the DVM reading in steps (f) and (h) is the source effect voltage and should not exceed the value
listed in the Performance Test Record Form for the appropriate model under CV SOURCE EFFECT.
CV Noise (PARD)
Periodic and random deviations (PARD) in the output (ripple and noise) combine to produce a residual AC voltage
superimposed on the DC output voltage. CV PARD is specified as the rms or peak-to-peak output voltage in a frequency
range from 20 Hz to 20 MHz.
a.
Turn off the supply and connect the output as shown in Figure 2-1 to an oscilloscope (AC coupled) between the (+) and
the (-) terminals. Set the oscilloscope’s bandwidth limit to 20 MHz and use an RF tip on the oscilloscope probe.
b.
Turn on the supply and program the current to the maximum programmable value and the output voltage to the
full-scale value (see Table 2-3).
c.
Adjust the load for the full-scale current value (see Table 2-3) as indicated on the front panel display.
d.
Note that the waveform on the oscilloscope should not exceed the peak-to-peak limits in the Performance Test Record
Form for the appropriate model under CV NOISE (PARD).
e.
Disconnect the oscilloscope and connect an AC rms voltmeter in its place. The rms voltage reading should not exceed
the RMS limits in the Performance Test Record Form for the appropriate model under CV NOISE (PARD).
Summary of Contents for 6541A
Page 12: ...12 Verification Figure 2 1 Basic Test Setup CV TESTS CV TESTS ...
Page 18: ...18 Verification Figure 2 3 CC RMS Noise Measurement Test Setup ...
Page 30: ......
Page 32: ...32 Troubleshooting Figure 3 1 Top View with Cover Removed for 655xA 665xA Models Sheet 1 of 2 ...
Page 33: ...Troubleshooting 33 Figure 3 1 Top View with Cover Removed for 655xA 665xA Models Sheet 2 of 2 ...
Page 37: ...Troubleshooting 37 Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 1 of 4 ...
Page 38: ...38 Troubleshooting Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 2 of 4 ...
Page 39: ...Troubleshooting 39 Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 3 of 4 ...
Page 40: ...40 Troubleshooting Figure 3 2 Overall Troubleshooting Flow Diagram Sheet 4 of 4 ...
Page 51: ...Troubleshooting 51 Figure 3 5 No Display Troubleshooting ...
Page 52: ...52 Troubleshooting Figure 3 6 OV Will Not Fire Troubleshooting ...
Page 53: ...Troubleshooting 53 Figure 3 7 OV At Turn On Troubleshooting Sheet 1 of 2 ...
Page 54: ...54 Troubleshooting Figure 3 7 OV At Turn On Troubleshooting Sheet 2 of 2 ...
Page 55: ...Troubleshooting 55 Figure 3 8 Output Held Low Troubleshooting Sheet 1 of 2 ...
Page 56: ...56 Troubleshooting Figure 3 8 Output Held Low Troubleshooting Sheet 2 of 2 ...
Page 57: ...Troubleshooting 57 Figure 3 9 Output Held High Troubleshooting ...
Page 58: ...58 Troubleshooting Figure 3 10 DAC Circuits Troubleshooting ...
Page 60: ...60 Troubleshooting Figure 3 13 Serial Down Troubleshooting Sheet 1 of 2 ...
Page 61: ...Troubleshooting 61 Figure 3 13 Serial Down Troubleshooting Sheet 2 of 2 ...
Page 62: ...62 Troubleshooting Figure 3 14 Secondary Down Troubleshooting Sheet 1 of 2 ...
Page 63: ...Troubleshooting 63 Figure 3 14 Secondary Down Troubleshooting Sheet 2 of 2 ...
Page 64: ...64 Troubleshooting Figure 3 15 Slow Down Programming Troubleshooting ...
Page 65: ...Troubleshooting 65 Figure 3 16 Isolator Board Circuits Troubleshooting ...
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Page 87: ...Principles of Operation 87 Figure 4 4 Output Power and Control Circuits ...
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Page 145: ...Figure 6 1 Power Supply Interconnection Diagram for All Models ...
Page 146: ...Figure 6 2 AC Power Distribution Diagram for 655xA 665xA Models ...
Page 147: ...Figure 6 3 GPIB Board Assembly Diagram sheet 1 of 2 ...
Page 148: ...2 3 4 1 6 5 7 8 Figure 6 3 GPIB Board Schematic Diagram sheet 2 of 2 ...
Page 149: ...Figure 6 4 Front Panel Board Assembly Diagram sheet 1 of 2 ...
Page 150: ...Figure 6 4 Front Panel Board Schematic Diagram sheet 2 of 2 ...
Page 152: ...Figure 6 5 A1 Main Board Assembly Diagram for 654xA 664xA Models Only ...
Page 160: ...Figure 6 6 Left Tunnel Circuits Schematic Diagram for 654xA 664xA Models Only sheet 2 ...
Page 162: ...Figure 6 7 Right Tunnel Circuits Schematic Diagram for 654xA 664xA Models Only sheet 2 ...
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