Dual Voltage Input Power Supply
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
A power supply includes a bridge rectifier, a pair of smoothing capacitors and a control circuit. When a 240-volt input is supplied, the bridge rectifier acts as a normal bridge. When a 110-volt input is supplied, this is detected by the control circuit which closes a switch to reconfigure the bridge on capacitors to act as a voltage doubling circuit. Thus the power supply will automatically produce roughly the same DC output voltage with an input of 240 V or 110 V. A long time constant circuit is included in the control circuit so that voltage spikes are ignored.