Positive(+) to Negative(-) Voltage Inverter

This simpe circuit will convert the positive input voltage become negative voltage.

Schematic diagram:
Positive(+) to Negative(-) Voltage Inverter circuit diagram


Component list:
Part Total Qty. Description
R1 1 24K 1/4 Watt Resistor
R2 1 56K 1/4 Watt Resistor
C1 1 3300pF 25V Ceramic Capacitor
C2 1 47uF 25V Electrolytic Capacitor
C3 1 10uF 25V Electrolytic Capacitor
D1, D2 2 1N4148 Silicon Diode
U1 1 555 Timer
MISC 1 Wire, Board


Notes:
  1. 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.
  2. For better regulation, a 79LOxx series regulator can be used.
  3. A zener diode may also be used to regulate the output voltage.

2 comments:

  1. UnknownMarch 31, 2010 at 6:36 AM

    ERRORS IN DESIGN:
    1) PIN 4 needs ground
    2) R1 and R2 are connected to pin 7 NOT to Vcc.
    3) The values of R1 and R2 are switched

    Please verify the schematic before post.

    ReplyDelete
  2. AnonymousJuly 3, 2011 at 1:16 AM

    Alvaro,
    pin 4 is a reset pin it connects to +vcc
    R2 is between pins 6,2 to 7.not pin 8.
    R1 and R2 values are reversed

    ReplyDelete