"Ignoramus8558" wrote in message
.. .
We were playing with my son last night and made a toy railroad
gate. It would open and close based on a relay signal from a momentary
switch that is activated when a train comes near the railroad
intersection.

It worked, kind of.

My problem is that the DC motor (pulled from a demolished HP X-Y
recorder) would overheat from being under power constantly.

I would like to find a little 12 VDC motor that could survive a locked
rotor condition indefinitely, or some other simple solution. A little
solenoid with a dual coil (pulling and holding) also comes to mind. I
need something that can be bought for a few bucks at most or made
easily, and I am out of ideas.

i

So after looking at all these electrical solutions I have to wonder why you
can't just do it mechanically. Put a pair of washers on the shaft and a jam
jut. Tighten the jam nut just enough to hold the gate at any position.
Power to motor only to move the gate and de-power it otherwise. 'Course
this assumes that the motor torque capability is way more than you need for
a simple model railroad gate. Very cheap. OK reliability. May have to play
with it to keep it from loosening up.

Have fun in any event.