Re: Ampro New Educational - motor woes, issues and solutions
Many years ago, I used to have an Ampro, that I assume was similar to yours.
This also had the common problem of this type of centrifugal speed regulator acting directly on the the motor. (Nice smell though!)
Kenwood, on their very early food mixers used exactly the same system, & even with a capacitor / snubber across the contacts, they suffered a similar fate. Some early portable reel-to reel recorders also used the same method, only of course with a with a D.C. motor. Later recorders, used the same contacts, to switch a transistor, thus relieving the contacts of their inductive load.
If you are going to use this projector regularly, then I wonder if it might be possible to use a similar approach, only of course for A.C.
You could isolate the contacts, & use them to switch an electronic solid-state relay which in turn controlled the motor.
Just an idea of course, you may wish to keep it original.
I wish you luck with it.
David.
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