Month: May 2019

Notes on power supplies and tube rectifiers

“To fully understand why this requires the use of a rectifier with a separately heated cathode, it is only necessary to draw the equivalent circuit of a power supply”…”Since there is no completed d.e. circuit, no d.c. current flows; no flowing current means no voltage drop across [transformer winding resistance and choke resistance]. Therefore the entire 550 volts appears across the filter capacitor, the open […]

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Notes on Output Transformers

“At low excitation levels, the inductance of the output transformer decreases, the phase shift increases and the tops of the square wave tilts. A high-level square wave will appear better that a low-level one at low frequencies. Similarly, high powers at high frequencies will clip any supersonic peaks in the response and improve the appearance […]

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