Throttle Questions

I run LGB trains, and I am considering building a pulse-width modulation throttle to enable better low speed control (I think it would be a fun project to build a nice custom throttle).

I have read on a few websites that some motors (such as those in LGB engines) do not react well to PWM power.

The LGB website, for example, recommends ONLY using an LGB power pack.

My basic question is two-fold:

First: Is PWM bad for LGB engines?

Second: Does anyone have recommendations for power supply/throttle schematics?

-Paul

Reply to
Paul Lizanich
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LGB is predisposed to tell you to use a LGB power pack as that is advertising to sell the powerpacks. The big thing here is the frequency of the pulse and the force of it. Higher frequencies smooth out with the inductance of the motor but don't provide the low speed that lower frequencies do. The longer pulse provides more power to the motor but also with efficient motors, the motor accelerates faster and hits the drivetrain harder causing possible wear. This can be migitated by providing a DC level in addition to the pulse at low medium speeds, fading to pure DC at higher speeds. I'll note that many things get started by the paranoia of some who sort of understand the process and have a searching mind that enjoys looking for problems. Go build the throttle and enjoy it.

-- There are more Democrats on the Calif. Special Election than Republicans! Go count if you don't believe me! Bob May

Reply to
Bob May

Unless LGB have changed the motor design greatly since they made my model, (unlikely) their motors have (by model railway standards) large diameter, large mass, slow speed armatures with robust bearings. They are classic for mains frequency 12-18 volt PWM type control.

Regards, Greg.P.

Reply to
Gregory Procter

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