GE DVM1950 - High Voltage Circuitry Explained; Half-Wave Voltage Doubler Circuit Operation

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High Voltage Half–Wave Doubler

The half wave voltage doubler circuit consists of the secondary winding of the high voltage transformer, high

voltage diode (rectiﬁ er), and the high voltage capacitor. The high voltage diode allows alternating current (AC)

to ﬂ ow in one direction only and rectiﬁ es it to pulsating direct current (DC).

The high voltage capacitor is able to store energy on one half of the AC cycle and release it on the other half

cycle. During the ﬁ rst half cycle of operation, the secondary winding of the transformer supplies 2000 VAC to

the capacitor. Current ﬂ ows through the diode and returns to the transformer for a complete circuit. This half

cycle of the AC charges the capacitor to approximately 2000 VDC.

During the second half cycle of operation, the current ﬂ ows in the opposite direction, and again supplies

2000 VDC to the circuit. This allows the capacitor to discharge its 2000 VDC on top of the 2000 VDC

generated by the secondary winding, creating an approximate total voltage of negative 4000 VDC.

The negative 4000 VDC causes the magnetron to conduct current and oscillate at 2450 MHz. The ﬁ rst half

cycle and the second half cycle become one complete cycle, repeating with input power frequency at 60 Hz.

Primary

Winding

at 120 VAC

Secondary

Winding at

2000 VDC

Magnetron

Capacitor

Diode

Filament Winding