Complete regulator

370

08:14:45

A linear regulator with electronic circuit breaker instead of a current limiter. 

published 11 years ago

Lousewort

11 years ago

As a complete amateur I have to express my appreciation of the current protection circuit. It is really elegant imo. Can anyone tell me the function of the 2.2k resistor between the first ans second transistor in the darlington pair? Cant seem to figure that out.

thebugger

11 years ago

I always prefer to give the emitter a ground reference. Whether its a 2.2k or 1Mohms it doesnt matter. You can also put a capacitor there for smoother transient response.

Lousewort

11 years ago

Ok thanks for the answer. How would a ground reference affect the behaviour of the circuit? Does it reduce the voltage at the base of the pass transistor? I am afraid I still dont get it.

thebugger

11 years ago

No it wont affect it in almost any way. It wont reduce anything its just imagine the power transistor failing or disconnecting. The emitter of the driving transistor will become loadless. And from what I know all three legs of a transistor should be connected for it to work.

Lousewort

11 years ago

Oh! Thats why! I would never have thought of that. Thats the difference between a pro and a novice like me. Thanks.

thebugger

11 years ago

I cant say im a pro but at least advanced. With or without it there wont be much difference i just chose to put it. Though id prefer to put a cap there for smoother transient response.

rbrtkurtz

11 years ago

If I'm not mistaken, you see a 4K7 resistor and a 0.0047uF cap in series a lot of times for a ground reference like that.

thebugger

11 years ago

I prefer them in parralel and 0.0047uf is a bit low maybe 47uF

rbrtkurtz

11 years ago

You might be right. That's why I said, "if I'm not mistaken." ;)

Addramyrz

10 years ago

Is that "just for EC?" Trying to visualize a TIP*** with "4 pins"...

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