Transient Operation

2 - General Information

Transient operation enables the module to periodically switch between two load levels, as might be required for testing power supplies. A power supply's regulation and transient characteristics can be evaluated by monitoring the supply's output voltage under varying combinations of load levels, frequency, duty cycle, and slew rate.

Transient operation can be turned on and off at the front panel or via the GPIB (TRAN ON and TRAN OFF commands). Before you turn on transient operation, you should set the desired mode of operation as well as all of the parameters associated with transient operation. Transient operation may be used in the CC, CR, or CV modes and can be continuous, pulsed, or toggled.

Continuous	Generates a repetitive pulse stream the toggles between two load levels.
Pulse	Generates a load change that returns to its original state after some time period.
Toggled	Generates a repetitive pulse stream that toggles between two load levels. Similar to
	Continuous mode except that the transient points are controlled by explicit triggers instead of
	an internal transient generator.

Continuous Transient Operation

In continuous operation, a repetitive pulse train switches between two load levels. In the front panel, the transient commands are located under the TRAN key. Continuous transient operation is selected via the GPIB using the TRAN:MODE CONT command.

The two load levels in the transient operation are the previously described main level (immediate or triggered) and transient level for current, resistance, or voltage. The rate at which the level changes is determined by the slew rate (see slew rate descriptions for CV, CR, or CV mode as applicable). In addition, the frequency and duty cycle of the continuous pulse train are programmable. The frequency can be set from 0.25 to 10000 Hz at the front panel or via the GPIB (TRAN:FREQ command). The duty cycle can be set from 3% to 97% (0.25 Hz to 1 kHz) or from 6% to 94% (above 1 kHz) at the front panel or via the GPIB (TRAN:DCYC command).

Pulsed Transient Operation

Pulsed transient operation is similar to continuous operation with the following exceptions:

a.In order to get a pulse, an explicit trigger is required. The trigger can be an external trigger signal received via the TRIGGER input on the rear panel, the TRIG:SOUR function, the *TRG or TRIG commands, the ac line, the internal timer signal, or the front panel Trigger key.

b.One pulse results from each trigger. Therefore, frequency cannot be programmed. The main level, transient level, and slew rate are programmed as described for continuous operation. The pulse width is programmable from 0.00005 to 4 seconds via the GPIB (TRAN:TWID command).

Toggled Transient Operation

Toggled transient operation causes the module input to alternate between two pre-defined levels as in continuous operation except that the transient points are controlled by explicit triggers instead of the internal transient generator. As in pulsed transient operation, the trigger signal can be an external trigger signal, the GPIB GET function, the *TRG command, the TRIG command, or the ac line or internal timer signals.