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Old 19th Jun 2021, 12:41 pm   #32
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Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 11,352
Default Re: GEC BC402 receiver.

Originally Posted by Dorian27 View Post
Well the reading with R35 disconnected is 140v dc and rising as valve warms.
Under normal circumstances with R35 disconnected that voltage should rise to the peak value of your mains supply voltage, the peak value of the mains supply voltage is easy to calculate, it's the mains voltage (RMS) multiplied by 1.414, for instance if your mains voltage was 240 volts AC then the peak voltage would be 240*1.414 which would be 339 volts peak AC, the voltage across the reservoir capacitor (C58) would rise to that voltage but that voltage would be DC.

That's one of those things that should be learned early on and never forgotten along with Ohms Law and the fact that all circuits are potential dividers.

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