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Constant-current mode operation -11 – AMETEK SGI Series User Manual

Page 63

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Sorensen SGI Series

Calibration and Verification

M550221-01 Rev AA

3-11

3.2.4 Constant-Current Mode Operation

In Constant-Current mode operation, the output current is regulated at the
selected value while the output voltage varies with the load requirements. The
current could be programmed either through the front panel or by the remote
analog current programming input; see Section 3.10. To verify operation in
Constant-Current mode, follow these steps:

1. If the output had been previously energized, allow 5 minutes for the

output capacitors to discharge. Connect a high current DC ammeter
across the rear panel positive and negative output terminals, observing
the correct polarity. Select wire leads of sufficient current carrying
capacity and an ammeter range compatible with the units maximum rated
output current.

Note:

Verification that the supply could source rated output current,

without measuring the current with an ammeter, but using only the front
panel meter, could be performed by shorting the output terminals
together.

2. Turn on the power supply.

3. If the default power-on state had been previously configured to be OFF,

when the supply reaches the Home menu Page 1, enable the
output by pressing “Output On/Off”.

4. Enter the Default Programming menu by pressing either of the

voltage, current, or overvoltage front panel keys:

5. Program the Voltage to 10% of rated output (this programs the voltage

above zero to enable supplying output voltage while in the constant-
current mode). See Section 3.8.1 for more details on programming.

6. Navigate to Current programming. With the Editing Arrow adjacent to

“Set Curr”, press and hold the NavPad up arrow and observe both the
front panel current display and the output of the DC ammeter begin to
accelerate up. The output current should increase from 0 A to the
maximum rated current of the supply. The front panel display and DC
ammeter readings should track within the accuracies of the meter and the
front panel display.

7. Verify the front panel Constant Current Mode indicator is on.

8. Program the Voltage and Current back to zero.

9. Turn the power supply off.

10. Allow 5 minutes for the output capacitors to discharge and disconnect the

ammeter or short from the output terminals.