Keysight E3630A, Operating And Service Manual

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4 Load Considerations
40 Keysight E3630A Operating and Service Manual
Pulse Loading
The power supply will automatically cross over from constant-voltage to
current-limit operation in response to an increase in the output current over the
preset limit. Although the preset limit may be set higher than the average output
current, high peak currents (as occur in pulse loading) may exceed the preset
current limit and cause crossover to occur and degrade performance.
Reverse Current Loading
An active load connected to the supply may actually deliver a reverse current to
the supply during a portion of its operating cycle. An external source cannot be
allowed to pump current into the supply without risking loss of regulation and
possible damage to the output capacitor of the supply. To avoid these effects, it is
necessary to preload the supply with a dummy load resistor so that the supply
delivers current through the entire operating cycle of the load devices.
Output Capacitance
An internal capacitor across the output terminals of the supply helps to supply
high-current pulses of short duration during constant-voltage operation. Any
capacitance added externally will improve the pulse current capability, but will
decrease the load protection provided by the current limiting circuit. A
high-current pulse may damage load components before the average output
current is large enough to cause the current limiting circuit to operate.