DC-to-DC Control (Converters and Choppers)

Originally in the 1970s and 1980s, the conversion of dc voltage to a different value of dc voltage was accomplished with a circuit called a chopper. The chopper was originally specifically designed to convert a fixed dc voltage into variable dc voltages primarily used to control the speed of dc motors. Since dc voltage is not readily available as a supply source in industry, these circuits must rely on a rectifier circuit to change ac supply voltage to dc. In this section we will treat these circuits from the point where dc voltage is supplied to them from the rectifier circuits. In this sense, they will be classified as a dc-to-dc converter. When troubleshooting these circuits, one must test the rectifier circuits to ensure a sufficient supply of dc voltage is available, even though the circuit diagram does not include the ac-to-dc rectification.