Hello
I have looked hard and long at this very matter and have some conclusions that I can offer.
My original controller was a H&M Safety Minor, this is a variable voltage controller/transformer and as such was considered very high tech in its day. In the mid 80's I replaced the selenium rectifiers for modern 5 amp bridge rectifiers, I also removed the half wave facility which has no place with todays motors! This controller still works today and provides solid performance on my test track. There are a number of safety enhancements that I also made for little or no cost.
Also on my test track I use a Kent Panel Controls hand held switchable feedback controller with reduced feedback. This is the best of both worlds. I hardly ever use the full feedback (reduced by me) setting and in fact I find that modern high efficiency motors hate this and actually run slower and hotter! The minimum setting provides good control over a wide range of motor types.
And my last and main controller is a Gaugemaster hand held normal darlington pair controller. This works fine with all motor types and is quite safe! It is fed by the AC output of the Safety Minor :-)
All in all, older motors will benefit from the kind of output you get from the older controllers but always full wave rectification! never use pulse. Never use feedback on coreless motors and avoid it for modern motors.
To answer your question, look at a Gaugemaster Combi controller with its 1.1 amps output this should be fine for your older models and safe for the newer ones.
Hope this helps
Mike
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