<p>PURPOSE: A power supply circuit is provided to increase power factors allowing an alternating voltage selected from multiple alternating voltages onto a load. CONSTITUTION: A multi level voltage output circuit(3) is equipped with an input terminal and multiple output terminals. The input terminal enters a voltage which changes the size periodically. The output terminals send out multiple voltages with different amplitudes. A switching circuit(5) provides one of voltages to a load(2) area. A power supply circuit is equipped with a switch and a controller. [Reference numerals] (2) Load; (3) Multi level voltage output circuit; (4) Rectifier circuit; (5) Switching circuit; (6) Charging and discharging circuit; (7) Voltage/current control circuit</p>
