Homemade Throttles

[Anonymous]

Some years ago, I can't remember exactly, but think it was in the mid 1980's MRR mag ran an article on building a throttle using resistors in a daisy pattern around an indexing rotary switch. Does anyone know the issue or how to build this throttle?

[Anonymous]

I don't know which issue of MR to check, but the principle of building a throttle using resistors as you describe is pretty straight forward. I believe you would have to include some momentum circuit to make it nice.

It seems that all you are doing is substituting a rotary switch wired in series with several resistors for a resistor mat. It would be nice to pretend you were notching up the throttle but without a momentum circuit your engine would jerk every time you went to a different setting.

There is some discussion of how to build a throttle in 'How to Detail Your Diesel Locomotives' and 'Easy Model Railroad Wiring'.

Good Luck - Ed

[Anonymous]

Thanks for the info Ed. I did build a couple of these throttles years ago, but the were lost to fire. Yes, the resistors did replace the variable resistor and still used a power mosfet. The plus was that all the parts were readily available and they were very inexpensive to build. When running engines that use flywheels I never noticed any problems with jerking and all my motive power carries flywheels. The momentum feature would be a big plus. I'll look into the sources you mentioned. Thanks again,
James

[Anonymous]

James, PETER THORNES' second book for Kalmbach is called 34 New Electronics projects for Model Railroading (I think). This is the book that has the throttles in it that you mentioned. Good Luck, Gary.