Other Parts Discussed in Thread: LM338
Hello everyone,
i have to deliver 5A to a varying load (between 1 ohm to 6 ohm) for about 1.2 seconds. My supply voltage is about 30V. On my first test circuit i used the LM338 voltage regulator and set it up as a current limiter like in the following figure:
The device works as intended and is limiting at 5A regardless of the load. The problem i have is that the device gets too hot on smaller loads so the thermal shutdown appears after about 100 ms depending on load. I need to provide it for atleast 1.2 seconds. And we dont have much space for a heat sink.
Now i was thinking about using an adjustable DC/DC stepdown converter or something similar. The idea is to adjust the output voltage to the amount i need for the 5A. I already looked through some step down converters but i only found ones where the output voltage is set by feedback with voltage divider on the output. Is there a device where i can set the output voltage via output-current like in the figure above with the LM338? Thanks :)
Best regards
Christoph