AVR-Chat

> From: Dave VanHorn
> 
> 
> >1) There are a mind boggling number to choose from (transistor, 
> >darlington, fet, etc.).  Can you give me some guidance as to a 'general 
> >purpose' device for this type of use and what general conditions the 
> >device would not be suitable.
> 
> Each type has it's strengths.
> Two things to look at carefully, are speed, and current transfer ratio.
> Most are relatively slow, and have a ctr that results in less 
> output current than is put in.  There are exceptions to both rules.

Thanks for the pointers Dave.

> >2) If driving a low current PC board relay is it good practice to 
> >connect the coil directly to the AVR (w/snubber diode) or 
> should I use a opto here too?
> 
> I don't think you need an opto, but I'd definitely use a transistor.

Yes, I'm currently using a transistor but didn't know if a more preferred
practice was to use an opto.  I'll continue with the transistor.

Cheers,

Chuck