12V controller from a battery?

[Anonymous]

Another newbie question:

I would like to power a setup using a solar panel. I have tested it out with a 9000mAh UPS battery, and it seems to run well (small track) for a couple hours at least. I could use the solar panel to charge the battery and then the battery to run the track easily enough, but I haven't found a controller unit that will vary power going to the track.

I'm sorry I'm not being very coherent, but if anyone has any tips for something like this they would be much appreciated!

david

[nfmisso]

David;

Basic you need a transistor throttle, disconnect the transformer and the rectifier. Or you could be build one. All you need is a transistor, a potentiometer, a couple of resistors, a fuse and a dpdt switch.

[rrinker]

Do NOT forget the fuse! The instantaneous current from a lead-acid battery like that is - well, a LOT. It's enough to weld a screwdriver accidently shorted across the terminals to the terminals. It's enough to certainly MELT any model locomotive.
Do NOT forget the fuse!

--Randy

[Jetrock]

Look for wiring diagrams for building your own controller--many such circuits are intended to be used wiht a 12V DC power supply, which it sounds like you are supplying. I have seen diagrams around for micro-layout powerpacks based on a 9V battery, a potentiometer, and a transistor...unfortunately I don't know where one would find it!

[nfmisso]

Here are some:
http://dan.pfeiffer.net/train/throttle.htm
http://home.cogeco.ca/~rpaisley4/CircuitIndex.html#1
http://users.rcn.com/weyand/tractronics/articles/ccartcl/ccartcl.htm