Olin wrote regarding 'Re: [EE] means of dimming auto tail light?' on Mon, Nov 28 at 08:14:
> Sounds like a great job for a 16F630.

Coincidentally, I just received a pair of 16F630s with a Digikey order
a couple of days ago - picked up because "someone" helpful suggested
that I use them on my other project.  How'd you know? :)

> chassis ground and the high side is switched.  In that case you need a high
> side switch, which would be either a bipolar (PNP) or FET (P channel).  I
> like the P channel FET better, because you'd probably dissipate a watt or
> two in the base drive from the PNP.  That by itself isn't a big deal
> considering its driving a 25-30 watt bulb, but now you need a power resistor
> and some way of making sure it can get rid of the heat.

Thanks for the circuit suggestion - that helps out quite a bit.  I did
some reading on FETs in general this morning, and they do sound like
they'd be a good choice.  The suggestion to use an IRF7416 is
appreciated, as well - but I've never worked with surface-mount stuff.
Is it reasonable to use a regular soldering iron to attach those
things, or would I maybe be better off looking for a through-hole
equivilant, like something in a TO-220 package?  I'm using Eagle to
create the board and having a local shop make it, so it doesn't make
much difference from a layout perspective (as far as I can tell) - but
I'm a bit concerned about things like heating the chip up too much,
etc.  Or would this be like any other IC in that regard?  It looks
like the pinout won't exactly be super demanding with regards to
soldering adjacent pins together, which I guess is my main concern
with SMT.

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