how efficient would this be?

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how efficient would this be?

Post by daguuy » Sat Oct 28, 2006 10:58 pm

i was fiddling around the other day with a potentiometer/big transistor to act as a volume adjust thing for an amp i'm trying to make and thought it might be useful in portablizing stuff too. here's what it is:
it works great with getting whatever voltage i want but how efficient is it? would it's efficiency be more like a linear regulator or dc-dc convertor?

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Post by codeman » Mon Oct 30, 2006 12:58 pm

If you look inside a linear regulator you'll baically see an op-amp controlling the current in a BJT to keep the output voltage constant, sort of similar to that you have there.

The efficiency of the DC-DC converter comes from the fact that it switches. It's not on 100% of the time like a linear regulator is. It changes dynamically with the load to improve its efficiency.
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Post by gannon » Mon Oct 30, 2006 1:14 pm

A lot of devices (including many NOACs) use transistor/resistor/diode combos for making the 5V needed.

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