This simple and inexpensive circuit can produce a dual (positive and negative) voltage from a single supply input. It is therefore extremely useful for powering op amp and other circuits that require a dual voltage from a single battery. The circuit will operate at an input voltage from around 5V to 20V and produce a output from +-2.5V to +-10V.
| R1 | 1 | 1M Linear Pot | |
| C1,C2 | 2 | 15uf 25V Electrolytic Capacitor | |
| U1 | 1 | LM380 Audio Amp Chip | |
| MISC | 1 | Heatsink For U1, Binding Posts (For Input/Output), Wire, Board |
1. U1 dissipates around 1W and will therefore require a heat sink.
2. R1 is used to equalize the outputs. The first time you use the circuit, it should be set to mid range and then adjusted with the aid of a voltmeter. Measure each output while adjusting. The circuit is calibrated when both outputs read the same voltage (either positive or negative).