On Thu, 2009-01-15 at 16:21 -0500, DJ Delorie wrote: > > But just to make sure that it doesn't ride "on the edge" at least > > I'd try some rapid load changes. > > Good idea. Hey - a flashlight bulb makes a handy 0.9A 5V load! Nope, > no problems, and pretty good regulation. > > One of these days I'm going to make a digitally-controlled load. It's > just a monster FET with some control circuitry, right? Not digital, but this is similar to a load circuit I built in the lab. Its a voltage programmable current sink, although only starts working about a few volts. I've used it to discharge up to about 40A. The actual circuit ended up with most of RLoad in the emitters of the FETs to ensure better balancing. For low voltage sources, I drop Rload as pictured all together, and rely on each FET's (10R IIRC) emitter resistor. Sorry, I don't have the component values to hand. (The schematic was drawn as an idea, it was then built on a breadboard and used - not much more was done with it). If its of interest, I've got the circuit and board layout for the small board which houses the current sense instrumentation amplifier. -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!)
Attachment:
linear_load.sch
Description: application/geda-schematic
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