0 Regulated Negative Power Supply using 79xx IC

This is a regulated negative power supply circuit using the 79xx IC series. These regulators can deliver current around 1.5A at a fix negative voltage. The common regulated voltages are -5V, -6V, -8V, -9V, -10V, -12V, -15V, -18V, and -24V. The regulator IC is the complement of 78xx regulator IC.

Negative power supply schematic

Part List:

T1 - see minimum input voltage below for reference

D - rectifier diode rated 2A with minimum voltage of 50V

Cin - 220uF electrolytic capacitor (- to IN and + to GRND)

Cout - 10uF electrolytic capacitor (- to OUT and + to GRND)

The table below is the list of regulator IC and the minimum input voltage required to maintain the output voltage.

Input voltage table

79xx IC come in TO220 casing. The pin connection is shown below.

TO220 casing

Pin 1 is the "GRND" pin, pin 2 is the "IN" and pin 3 is the "OUT" pin. Take note that these pins are different from the pins of 78xx IC series since "IN" and "GRND" pins are interchanged.