SCR-Controlled Digitally Programmable AC Power Supply

A digitally programmable ac power supply was designed, built, and tested. Its output voltage may be programmed to be any one of 41 equally spaced voltage levels and may be switched from any level to any other level in one 60-Hz period (16.67 ms). The switching of voltages is accomplished by turning on and off individual silicon controlled rectifiers (SCR's) in a network of 14 pairs of SCRs. The concept of this power supply is readily extendable to more or fewer voltage levels or higher or lower output currents or voltages than the particular supply described.