Pwr suppley Problem I made a power supply with 3 paralelled LM338 Regulators in paralell (24V 12A trans), with 2 paralelled 20A rectifirs, worked great for 1 week, then all of a sudden, output dropped to 2 amps max (from 15A), , all componed seem to check out ok, getting full current out of filter caaps past rectifiers, any ideas, tried substituting a good regulater, and same thing, any ideas.
Pwr suppley Problem
Nov 20, 2008
3 Replies
Sorry.. I'm a very visual person.. Schematic please..
Perhaps see:
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Page 14 has an example of paralleling regulators.
But what bugs me, why parallel regulators??? I'm inclined to get the same function by paralleling transistors, use feedback and a Vref.
D from BC myrealaddress(at)comic(dot)com British Columbia Canada
Simplify first. Get one regulator working by removing other parts - then reintroduce the second, etc.
Most obvious failure is in low value sharing resistors. Perhaps these were not good for 5A and they are now open/higherZ.
A schematic would be nice.
RL
I wonder if Scott used current equalizing resistors, as NSC recommended in the examples in the datasheet?
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