For example, assume that the CC mode is active, the slew rate is at the default setting (maximum rate), and the applicable transient operation parameters have been set as follows:
HPSL Command | Description |
TRAN:MODE CONT | Sets continuous operation. |
CURR 5 | Sets main current level to 5 amps. |
CURR:TLEV 10 | Sets transient current level to 10 amps. |
TRAN:FREQ 1000 | Sets transient generator frequency to 1 kHz. |
TRAN:DCYC 40 | Sets transient generator duty cycle to 40%. |
TRAN ON | Turns on transient operation. |
Figure 2-4 shows the waveform that would result in this example. The load input current will slew to and remain at 10 amps for 40% of the period (400 μs), then slew to and remain at 5 amps for the remaining 60% (600 μs) of that cycle.
Figure 2-4. Continuous Transient Operation
The load starts conduction at the main level (in this case 5 amps). When transient operation is turned on and at a time specified by the frequency setting the input level starts increasing at a rate determined by the slew rate. When the value specified by the transient level setting is reached, it stays there for the remainder of the time determined by the frequency and duty cycle settings. After this time has elapsed, the input level decreases to the main level again at the rate specified by the slew setting and stays there for the remainder of the period prescribed by the frequency setting.
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 GPIB GET function, the *TRG common HPSL command, or the TRIG subsystem HPSL command.
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). Pulsed transient operation cannot be programmed at the front panel.
c.There may be a delay between the generation of the trigger and the appearance of the pulse at the load’s input. For pulse widths of 17 ms or greater, delay is less than 1.6% of the pulse width. For pulse widths of less than 17 ms, delay is less than 4% of the pulse width.
In this example, assume that the CC mode is active, the slew rate is at the factory default setting (maximum rate), an external trigger input is connected to the Electronic Load’s rear panel, and the applicable transient operation parameters have been set as follows: