What's in a controller? Build yer own perhaps?

[Software Tools]

which got me to wondering exactly what is in them.

The basics are:
[*]An adequately rated step-down transformer to ~24VAC (or lower voltage if you prefer)[*]A bridge rectifier[*]Usually some solid state electronics that accepts control signals from "controls" (that is, usually a "speed" signal and a "direction signal) and delivers power to the track.[*]Something to quickly manage short circuits or other overloads on the track output. Can you build one yourself.... yes, if you know what you are doing with power electronics - but IMO, for anything much over a couple of amps of current it is generally simpler overall to buy a commercial unit.

YMMV

Cheers,

Bill

 

[GAP]

You can use a LM338 5amp regulator use the TO3 can type it is fully protected for temperature and current limits
cannot find how to put on an attachment so i cannot design one for you but if you let me have your email i will do it for you.

Railway42

This is a circuit I used with LM338, I just left out the meters etc.
I have also run this of a battery instead of transformer/rectifier input

 

[GAP]

Here's a shot of the controller with heatsink.

You have to use a special washer system - to isolate the transistor from the chassis, but that allows transfer of heat (forget the name now - senility looms)

Insulating washers, used to be made of Mica, but newer ones use a rubber compound, there are also nylon insulating inserts for the securing bolts.
Kit available from Jaycar.
http://www.jaycar.com.au/productView.asp?ID=HP1172
A heatsink compound can be used to aid heat transfer.
http://www.jaycar.com.au/productView.asp?ID=NM2011