izua
Joined: 31 Oct 2006
Posts: 63
Helped: 2
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 09 Dec 2006 14:20 Power distributer, 5 terminals, "active" led |
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I recently realised i need a power splitter/distributer, since it becomes really messy having aligator clips to all circuits i'm testing.
I was thinking of making a power supply, with one output of +5 (TTL), another of +9 (CMOS, but agian, +9 is widely used, in audio processing, so i guess i need that too), and another one, which will be setable.
Now, i'm just trying to make the polarity switch and the led which will light when one of the outputs is used (i think it will have 5 or 6 outputs). I was thinking of driving each output through a base-emitter junction, and the led, through a collector-emittor, in a NPN.
But what transistors should i look for? I was also thinking, if one of the circuits will need more than the base-emitter junction could allow through, what will happen? Will it get the max, or the transistor will burn out?
I was thinking of something like 250 mA at most. Anyone knows some transistors for this job?
Now, i was also thinking about the polarity switch. a DPDT switch seems to do the job. Here's the way i thought of it. Is it safe? If this dpdt will make the other connection before breaking the first, i guess my transformer will be shorted out.
the two circles in the lower right is an actual pair of terminals: V+ and GND - i'll hook a power jack or maybe even aligator clips there, hehe.
thanks.
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izua
Joined: 31 Oct 2006
Posts: 63
Helped: 2
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| 13 Dec 2006 12:49 Re: Power distributer, 5 terminals, "active" led |
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come on? anyone?
i realised my design is faulty, since i can't use a current via base-emiiter, since i'll burn the transistor up.
basically, i want a power source (like an adapter) with multiple outputs. when one output is connected, its led will light up, when one output is not connected to anything, its led won't glow. pretty simple i guess 
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