Simple 100W inverter circuit

Simple 100W inverter

An Inverter is a small circuit that converts the direct current (DC) to alternating current (AC). The power of a battery is converted into main voltages or AC voltage. We can use AC power for electronic appliances like television, mobile phones, computer etc. The basic function of an inverter is to convert DC to AC. Step-up transformer is used to create main voltages.

Block Diagram of An Inverter:

Block Diagram of An inverter

The block diagram explains that battery supply is given to the MOSFET driver where it will oscillate the DC current and the resulting oscillate current is given to the step up transformer then step up transformer give AC Power.


  • IC – CD4047 – 1 
  • MOSFET IRF540 -2
  • Resistor – 330 ohm – 1
  • Resistor – 220 ohm – 2
  • Resistor – 1k ohm – 2
  • Resistor – 390k ohm – 1
  • Diode – 1N4007 – 1
  • Switch – 1
  • Capacitor – 0.01uF – 1
  • Capacitor – 0.1uF
  • Transformer – 150VA – 1
  • 12v Battery-1

Circuit Diagram


Working Detail of This Inveter

CD4047 is a multi-vibrator with very low power consumption. It can operate in mono-stable multi-vibrator and also astable multi-vibrator.  In astable multi-vibrator mode it operates in free running or gate able modes and also provides good astable frequency stability. It generates 50% duty cycle that creates a pulse which is applied for inverter circuit. This is the main use of IC CD4047.

IRF540 is a N-channel MOSFETthat is mainly used in switching regulators, switching converters relay drivers etc. The reason behind using MOSFET in the INVERTER circuit is a high switching transistor that work in very low gate drive power and have high input impedance.



  • In this circuit diagram we observe that 12V battery is connected to the diode LED and also connected to the pin8,PIN7,PIN9 and PIN12 of the IC. The positive power supply is also to pin 4,5,6 and 14 which are astable and  complement astable of  the IC CD 4047. The Basic function of  Diode in the circuit is to prevent reverse current.
  •  CD4047 IC works in the astable multi-vibrator mode To work it in astable multivibrator mode we need a capacitor which is connected between the pin1 and pin3 of IC. Pin2 is connected through resistor and a variable resistor to change the output frequency of inverter. The pins 10 and 11 of the IC are connected to the gate of the IRF540. The output frequencies of pin 10 and 11 generate frequency with 50% duty cycle.
  • The output frequency is connected to the mosfets through 220 ohm resistor which will help to prevent to the loading of the mosfets. The main AC current is generated by the both MOSFIT (IRF540). Here Mosfit act as a two electronic switches.
  • The output AC is given to the step up transformer of the secondary coil from this coil to increase AC voltage. These voltages depends on the power of transformer.
  • In this way DC is converted into AC Current.


  • Battery can be a 12V/ 6Ah lead-acid battery.
  • MOSFETs must be fitted ona proper heat sink to protect.
  • Transformer can be a 9-0-9 V primary, 230V/110v secondary, 150VA transformer.
  • The is a very simple one suitable for low-grade applications not for high watts output.

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