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Old 6th Jan 2023, 7:11 pm   #24
sourbiscuits
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Join Date: Sep 2022
Location: Amsterdam, Netherlands.
Posts: 124
Default Re: Uher Royal Stereo 784

Quote:
Originally Posted by Analogue man View Post
Quote:
Originally Posted by sourbiscuits View Post
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Originally Posted by Analogue man View Post
It is possible to control the speed (downwards) on a motor that has a run capacitor by connecting a rheostat across the capacitor terminals and connecting the supply wire to the wiper of the rheostat but once the wiper reaches just beyond the mid point of the rheostat the motor will start to run backwards. I did this on some older Grundig recorders in my (much) younger days.

That's helpful thank you! In theory, could I not hook up the rheostat directly between the power source and the motor (in case there isn't a run cap)?
No, the motors are mains frequency synchronous and hence will always try to run at the normally correct speed but produce less torque.
Thank you for the response! I wasn't too hopefull it would work that way. Either way, from the small research I've done, in case there is no run capacitor, I think using a Variable Frequency Drive should do make this work, or am I wrong?
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