Notch-Programmed Appliance Coupler for Low/High Utility Voltage Discrimination
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
This article describes an appliance coupler which provides a simple, effective mechanical means of electrically programming a switching power supply front end for low (100-125 VAC) or high (200-240 VAC) utility voltage applications. A standard IEC appliance connector is used with no internal wiring variations in the connector or cord. Typical off-line switching power supplies employ a rectifier and capacitor-filter combination to establish a DC voltage in the range of 200 to 400 VDC, nominally about 325 V. Switching circuits convert and regulate this voltage into the desired power supply output levels. To derive a common value of bulk voltage from the worldwide menu of AC utility voltages, a bridge rectifier configuration is employed for line voltages of 200-240 VAC and a doubler configuration for 100-125 VAC.