Thread: Philco Seventeener II
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  #88  
Old 07-05-2017, 11:28 PM
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jr_tech jr_tech is offline
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Simply replace the heater drop resistor with a diode... it will clip off half of the 122v sine wave. The resulting true rms voltage of the clipped waveform will be 0.707 times the input voltage. 1N4007 will work fine in this application.

jr
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