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Old 18th Oct 2021, 6:33 am   #7
JonSnell's Avatar
Join Date: Oct 2019
Location: Weymouth, Dorset, UK.
Posts: 184
Default Re: Singer 2502C pedal repair.

The motor is AC and you have a light dimmer circuit ib series with it.
The triac fires sooner or later on the AC cycles, later when the pot is higher resistance and sooner when the pot is lower resistance.
It will heat up when it receives a late phase power on, and as the speed is low, it will not cool properly;
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Valve equipment repairs since 1968
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