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how to make a speed controller for a washing machine motor

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speedibee:
Yes the motor has brushes . it was from an indesit 1100 spin washer . I think its called a universal motor

John Rudd:
Should be good for a lathe then... :dremel:

speedibee:
some motor photos and one of the original control panel

picclock:
I think these motors are DC controlled, and if memory serves me correctly mains powered via a full wave rectifier (or at least they used to be :-)). A simple controller can be made by using the  dc voltage generated by the motor rotation to trigger the thyristor when the rotation, and generated voltage falls.

Its a very simple circuit that gives excellent speed regulation vs load. The downside is that there is no mains isolation so that touching any part of the circuit could be lethal, so serious insulation and earth leakage protection mandatory.

Parts must be 400v rated (240*1.414), though the pot can be quite a high value, say 50k. Diac and thyristor to suite.

Circuit operation. Rippling DC from the full wave rectifier is fed to the Thyristor/motor series  circuit. The speed control pot wiper is connected to the diac and a capacitor. When the voltage of the wiper is greater than the diac voltage plus the motor generated voltage the diac will switch to conduction and discharge the capacitor into the thyristor gate triggering it. If the motor is too fast the voltage produced will be too high to trigger.

Best Regards

picclock

AdeV:
As my old washing machine has just decided to blow up (on top of a faulty door latch which required a screwdriver and some swearing to remove one's washed clothes), I am suddenly very interested in this thread, and I'm glad it's surfaced again as I'd forgotten all about it   :clap:

Just need to think of something to do with the old motor & speed controller circuit that's not a) lethal, or b) boring....  :scratch:

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