Foldback. If foldback protection is enabled (FOLDBACK ENABLED LED on) and the power supply switches to the prohibited mode (CV or CC), the power supply output will be disabled and the FOLDBACK indicator turned on. Press the FOLDBACK pushbutton switch to reset the foldback protection circuit and restore the power supply output. Unless the conditions (voltage setting, current setting, load resistance) that caused foldback are changed, the circuit will trip again when the output is restored. Pressing the FOLDBACK switch a second time after resetting foldback will turn off foldback protection if desired.
Error. If the power supply receives an invalid command (syntax error, out of range), either locally or via
Local Operation
The power supply is configured for local operation when the unit is turned on. Output voltage and current are both set to zero, and the OUTPUT ADJUST knob is configured to adjust output current (CURRENT indicator is on). Pressing the OUTPUT ADJUST pushbutton switch alternately configures the OUTPUT ADJUST knob to adjust output voltage and current, as indicated by the VOLTAGE and CURRENT indicators. Note that the OUTPUT ADJUST knob will vary whichever output parameter, voltage or current, is indicated by the VOLTAGE and CURRENT indicators, even when the other parameter is limiting the output.
By pressing the DISPLAY SETTINGS pushbutton switch the operator can observe the setting (limits) of both output parameters, rather than the actual output values. This allows the operator to set the current limit when the power supply is operating m CV mode, or set the voltage limit while in CC mode, without the necessity of disconnecting or adjusting the load.
When the power supply is under remote control (RMT indicator on), neither the VOLTAGE or CURRENT indicator is on and the OUTPUT ADJUST knob has no effect.
Constant Voltage Operation
To set up the power supply for constant voltage operation:
a.With power supply turned off, connect load to output terminals.
b.Turn on power supply. Hold in DISPLAY OVP pushbutton switch and set OVP ADJUST potentiometer for desired OVP trip voltage.
c.Ensure that CURRENT indicator is on, hold DISPLAY SETTINGS pushbutton switch in and rotate OUTPUT ADJUST knob to set desired current limit.
d.Press OUTPUT ADJUST switch once so that OUTPUT ADJUST knob controls voltage, and adjust output voltage to desired level.
e.If foldback protection is desired, press FOLDBACK pushbutton switch to enable this feature.
f.If a load change causes the current limit to be exceeded, the power supply automatically crosses over to constant current operation and the output voltage drops proportionately. If foldback protection is enabled, mode crossover causes the power supply output to be disabled. In setting the current limit, make adequate allowance for high current peaks that could cause unwanted mode crossover.
Operating Instructions 43
