Regulated dual power supply circuit from single battery source

How to create dual power supply unit using single battery for your lab prupose? Dual voltage power supplies are required particularly for op amp experiments and some of the instrumentation amplifiers. Some low power audio pre amplifiers also uses dual voltage supply. Here is a simple dual power supply schematic capable of producing +9V, 0V and -9V (dual polarity and ground potential) from a single 9V battery. You can create your own dual power supplies with different ranges of +Vcc and –Vcc such as +5V, 0V and -5V or +12V, 0V and -12V. This article gives the working and constructional details of the circuit schematic using single battery source.


Circuit diagram

Dual power supply circuit
                                                                 (Click on the image for enlarged view)

Components required

  1. NE555 timer IC
  2. Negative voltage regulator IC 7909
  3. Diode 1N4007
  4. Resistors (470Ω, 0.5W x 2)
  5. Capacitors (0.01µF; 220µF, 16V x 4)
  6. 9V battery


  • Timer IC NE555 is configured as a free running astable multivibrator oscillator. It provides approximately 100 kHz frequency. We have already discussed about astable multivibrator.
  • The frequency of the astable multivibrator depends on the values of capacitor and resistors associated with 555 timer circuit. Our astable frequency calculator will help you decide them.
  • The oscillating voltage (square pulse) is made ripple free using 1N4007 diodes and regulated to -9V by negative voltage regulator LM7909.
  • Use 5V battery if you need to create +5V, 0V and -5V dual power supply unit.
  • The operating voltage of 555 timer IC is approximately between 3V to 16V, so by changing the battery supply you can implement required dual power supply varies from 3V to 16V other than +9V, 0V and -9V supply.
Now power supply is ready for use in your lab. Feel free to ask for any help regarding the schematic. All the best. Cheers!

Pin out of 555 timer and 7909 Negative voltage regulator

26 thoughts on “Regulated dual power supply circuit from single battery source

  1. This is what i am looking for!!! I know a little of electronic. I has no transformer with dual power but I use battery to supply the circuit of Op-Amp but it's not work. I read a lot and search a lot to find this alternative to transformer. It's very useful. I will try this.

    • I guess you'r talking about using 12V input power source. Yes you can use 12V, then you'll get +12V but -9V only. To get -12V you can use 7912.

  2. hi, is it possible – in case we use lm317 (possibly with 12v mov) to supply power to 555 – then we can escalate the voltage???

  3. Tried the circuit on actual breadboard with components, does not work. Checked astable with oscilloscope, which is operating correctly. But no negative voltage generated by regulator. Circuit is a dud.

  4. Thanks for the design schematic; I’m looking to modify this for 12v battery and +/-12v output utilising a 7912 IC instead which looks perfect for my requirements.

    One question I did have was regarding the 7909 IC in your original design; the maximum operating voltage I could find for that IC was – 15v (down to – 35v) however your circuit is only supplying – 9v after the 555 timer.
    Have I misread the schematic or is there a version of the 7909 IC which operates at higher voltages than -15v?

  5. Can I Connect Two opposite terminal of battery? Will remaining terminals will give me +be and -ve?
    And will the wire drawn From The Connected terminal give me Grounnd

  6. I know that the 555 can only source about 200ma, so can the (-) current be increased by using the 555 output to drive a PNP power transistor base with it’s collector connected to the 79xx input and it’s emitter tied to 0v? I know that the rectifier diodes would also need to have a higher current rating.

  7. I built the circuit as shown and it does not work as described. The 555 output is a 0 to +12 volt square wave at 90.1 KHZ – so far so good. However, the output is a square wave which goes from (-) 6v to (+) 5v no load and with a 330 ohm load it shrinks to a square wave with a (-) 2v and (+) 1 volt swing with a (+) 8v, 1/2 usec leading edge.

    I triple checked the wiring, it is as shown on your drawings – any ideas or suggestions?


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