Consideration on efficiency and distortion in a power-factor-corrected constant-voltage constant-current AC power supply having variable capacitance devices

The new constant-voltage constant-current ac power supply is presented. Unique Variable Capacitance Device from our laboratory has been used as a linear reactance element in power stage. This circuit makes almost no distortion of output voltage waveform and a high efficiency can be obtained. To control the output voltage and current, and to correct input power factor, two Variable Capacitance Devices were employed as a linear capacitor. The unity input power factor can be obtained all over the constant-voltage constant-current region. At no load and at short-circuit load, the input current is almost zero. The relationship between efficiency and distortion is considered.