~14.3v powersupply Help needed

Thread Starter

Gator-4200

Joined May 24, 2013
9
The circuit will work as drawn, not with great regulation but you can use NPN transistors as an emitter follower after a regulator like this and get better performance than you have seen. But, as wayneh says you need more base current - lower your 100 Ohm resistor or eliminate it altogether. You should allow for an amp from your regulator - it will need to be on a good heatsink.

Be careful with the current sharing between the transistors - perhaps add a small resistor in series with the collectors of each - 0.3 Ohm would drop perhaps 1V at full current and swamp out the differences between the transistors ensuring they share properly.
This ^^^ :D
Right! Simply adding some 0.5 ohm 7 watt (best thing I could find in city) resistors to the collectors the load is regulated much better! only drops 1.25v tops. Would work well for... something not sure, but I learned stuff!
Anyhow I found some PNP transistors that will work for the job! I got 2 tip2955 and 4 more on the way. So I'll build the other powersupply with a variable voltage which will work better.
Thanks everyone for the help!
 

Thread Starter

Gator-4200

Joined May 24, 2013
9
I need about 20-25amps, but I have the parts now to make a 35 amp supply. so... That is the direction I'm headed.
Thanks anyway! :)
 
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