Automatic Selection of Line Voltage Tap for a Power Supply
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
A four-pin appliance coupler is used in connection with voltage- standardized wall plugs to provide an automatic selection of line voltage tap for a power supply. Switching power supplies can be designed to run on both the 100- to 120-volt and 200- to 240-volt AC types of utility lines by configuring the input rectifiers and filter capacitors in either a doubler or full-wave bridge configuration. The selection may be accomplished by using either a switch or a jumper. Transformer and ferroresonant supplies accommodate the dual-voltage input possibility by changing taps on the transformer. In any of the cases it is desirable to be able to easily change from one configuration to the other. The usual solution is a customer accessible switch, but this often results in an incorrect selection of input voltage.