operation of half wave rectifier type AC Voltmeter.
Half-wave Rectifier Voltmeter The d’Arsonval meter movement only responds to the average or dc value of the current through the moving coil. In order to measure alternating voltage with d’Arsonval meter, the unidirectional current flow. If a diode D1 is added to the dc voltmeter circuit, then a circuit that is capable of measuring ac voltage is achieved. Therefore, the AC voltmeter produces an output voltage, which is equal to 0.45 times the rms value of the sinusoidal (AC) input voltage signal alternating signal needs to be rectified first by using diode rectifier to produce