Best choice for driving power-devices from a DIO pin?

Suppose I have a TTL output pin, and I want to use it to switch something
that pulls a lot of current.

I've been driving a relay through a switching transistor. But are there
better alternatives?

In my ideal world, there'd be a DIP that I could control from a
microprocessor without having to mess about with transistors, and could
switch multi-amp current. Ideally switching fast enough that I could do
PWM control.

How close can we get?

--
The twentieth century was one in which limits on state power were removed
in order to let the intellectuals run with the ball, and they screwed
everything up and turned the century into an abattoir... We Americans
are the only ones who didn't get creamed at some point during all of
this. We are free and prosperous because we have inherited political
and value systems fabricated by a particular set of eighteenth-century
intellectuals who happened to get it right. But we have lost touch with
those intellectuals.
- Neal Stephenson

 

they make solid state relays with
isolation and low input voltage and
current to operate it.
also are the isolated photo
Fet switches which give you low
turn on R.

 

http://www.google.com/search?q=uln2803+data+sheet

Cheers!
Rich

 

On Sat, 24 Dec 2005 00:36:11 GMT in sci.electronics.basics, Rich

uln2803 cannot switch multi-amp current.