On 16/04/2011 00:46, V G wrote:
> But I don't understand why the high side sensing is difficult. Isn't it t=
he
> same idea? Just measure the voltage drop across the resistor? I'll just
> sample some nice diff amp from LT or something.
>
> With the low side sensing, I can just use a good opamp?

How accurate do you want this to be?
I would probably just use a 2N3055 and Fet with low side sense resistor,=20
plus a basic opamp with pot.
For displaying the current value you could use one of the dedicated=20
display modules with the intelligence built in, or a small PIC and 2/3=20
digits.
I know you said you have little time, but I would really advise spending=20
~15 mins watching the EEVBlog video - it's pretty much exactly what you=20
are looking for (just lower current IIRC), and roughly what is being=20
proposed by folk here. In any case, those 15 mins may actually save much=20
more trying to figure all this out.


--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.