Simple Regulated Power Supply Circuits

Figure 1.  Circuit Diagram for a Regulated Power Supply

The circuit in Figure 1 uses a full-wave diode bridge rectifier circuit to convert the household AC voltage to an unregulated DC voltage at capacitor C1.  The voltage at C1 is then fed into a voltage regulator IC which outputs a regulated supply voltage, i.e., a voltage that more or less remains at the same level despite changes in load.

Figure 2.  Circuit Diagram for another Regulated Power Supply

The circuit in Figure 2 uses a full-wave two-diode rectifier circuit to convert the household AC voltage to an unregulated DC voltage at capacitor C1.  The voltage at C1 is then fed into a voltage regulator IC which outputs a regulated supply voltage, i.e., a voltage that more or less remains at the same level despite changes in load.

In both examples, the regulator used is the 7805, which outputs 5V DC.  A broad range of other DC voltage regulator IC's is available in the market.  The voltage regulator must be attached to a heatsink if maximum allowable current is required in its operation.