Voltage inverter circuit Diagram
This voltage inverter circuit powering a dual supply op amp from a single battery problem. The circuit simply takes a positive voltage and inverts it.
It uses only one 555 timer and a few other passive components, so it doesn't add much in the way of size and cost to a project.
U1 1 555 Timer
R2 1 56K 1/4 Watt Resistor
R1 1 24K 1/4 Watt Resistor
MISC 1 Wire, Board
D1, D2 2 1N4148 Silicon Diode
C4 1 100uF 25V Electrolytic Capacitor
C3 1 10uF 25V Electrolytic Capacitor
C2 1 47uF 25V Electrolytic Capacitor
C1 1 3300pF 25V Ceramic Capacitor
V+ can be anywhere from 4 to 16V. -V is one volt less than V+. So for -12V output, use +13V input. The maximum current output of the circuit is about 280mA, more than enough for a few op amps. For better regulation, a 79LOxx series regulator can be used.
A zener diode may also be used to regualte the output voltage.