Quote:
Originally Posted by maxhifi
This is a single phase induction motor circuit, from a USSR made record player (circa 1977). This type of motor is known as a permanent split capacitor type. More common in European equipment versus our shaded pole induction motors.
R16 is used for fine speed control. I can't make sense of this circuit, why the diodes are there, etc. and I have never seen it done this way anywhere else. It looks like a strange form of non variable phase angle control, but I don't know what is the function of R14.
And more to the point, can I increase the resistors to make this thing work on 60Hz, or is it better to machine the pulley down?
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All AC motors are designed for the mains frequency. The circuit is a rather interesting approach to speed correction. It probably will only vary the speed, 10% +or-. The line frequency in some areas, isn't as precise, as areas using a power grid.
The only remedy is reducing the diameter of the pulley, by remachining.
