Hornby R965 Controller

[cybrey]

Apologies if this posted in the wrong place.

My late father left behind an N-Gauge set which I've decided to sell. Unfortunately its now all completely disassembled. It was setup with a whole of heap Digitrax kit which I've no clue how to configure / setup.

Before selling any of the engines I'd like to test them. I was wondering if using a Hornby R965 controller from an HO/OO set will work ok? (and not damage the trains).

Many thanks in advance for any help anyone can provide.

[Railwaygun]

This is an old controller and has a load dependent output voltage.

Hornby Train Controller
Product Code: R965

Production Details:
Controls the direction and speed of one locomotive. Input is 16v AC from the R964 mains transformer (not supplied, see above). Output is 0-12v DC to the track, plus non-variable 16v AC output for power-switched points, signals and other accessories. Supplied fitted with 760mm lead to Power Connecting Clip.

I'm not sure I would trust it with N gauge locos - perhaps an eBay spare or local model rail show would yield a cheap N scale controller.

I have a couple on the attic if interested - PM me

The inside info

http://www.scottpages.net/ReviewOfControllers.html



https://www.hornby.com/uk-en/forum/r965-controller/?p=1



Internally that there is a series wired rheostat that limits current rather than voltage. Being in series, when testing the output with a multi-meter, the multi-meter will have a high impedance measured in MegaOhms, thus there is NO LOAD across the R965 output when being tested this way. Thus, there is no current being drawn, thus there is no voltage drop across the control knob rheostat. Thus the output voltage will read constant across the control knob range. Think electrical theory 'open circuit' voltage reading.
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Easy way to test this theory is to put a dummy resistive load across the R965 output, then test with the multi-meter and measure DC volts across this dummy load. The dummy load now draws a current to force a volts drop across the internal rheostat. The control knob rheostat will alter the current being supplied to the dummy load, the change in current, changes the voltage across the dummy load. Basic Ohms Law theory. Suggest 150 ohms @ 2 watt for a test dummy load resistor.

[cybrey]

Many thanks for the quick and very detailed reply, I'll send you a PM.