Cableguy wrote:
Thank You Guys....!!!

I never expected this kind of foward help from a news group...
You guys rock!!!

I think that I willgo with the relay option, as it is cheaper for me, since
I don't even have a uP programer, and also attending to the caution notes
posted....

As far as the "mechanical design, I'm thinking on using a "blind" like
faceplate that rolls up and down...My only doubt is ...
Waht will happen if the motion is stoped by exterior interaction, like a
slider getting stuck'
What will burn first? The motor, the relay, or the fuse?

Anyway all that rest me to do is experimenting and give you guys a big THANK
YOU for all your input..

Nothing is going to burn if you do it right. Read on.

You may be able to use catalog # DCM-273 from Allelectronics.
It is used to adjust the side mirror in automobiles. Another
one might be DCM-276. Since this is a small mecnaism that will
require very little force to move, and the motor you use will
need to be physically small, it won't take a lot of current,
which brings us to the protection issue you asked about.

The wiring to the circuit must be protected by a fuse, of course.
Beyond that, you may be able to protect against a jam in the
mechanism with nothing more than a resistor in series with the
motor you use. For example, DCM-276 draws only 15 mA at 13.5 volts.
A 470 ohm, 1 watt resistance would cut the voltage to the motor to
about 7 volts, and the current to a little less than 10 mA. If the
mechanism jammed, the resistor drop the voltage even more, and
would limit the current to less than 30 mA, and the motor and
circuit should be fine. What will be required to provide protection
depends upon the motor you use.

Allelectronics has a nice range of micro switches in their
"snap-action switch" category. See, for example, catalog# SMS-223.
They also have a 12V DPDT relay you could use - catalog# RLY-622.
With a low current motor no spike protection will be needed.
If you want, you can add a snubber network (.1uf in series
with 100 ohme) across the motor terminals. You do not need a
protection diode across the relay coil. If you have the physical
space, you could add both the diode and the snubber network.

Ed