60-Watt Inverter

A simple inverter that designed using basic and low-cost electronic components converts 12V DC to 220V AC at a 50Hz square wave, making it useful for powering small household appliances up to 60W.

Components List

The following components are required to make this project.

Designation	Parts	Quantity
U1	IC CD4047	X1
Q1, Q2	IRFZ44N N-Channel MOSFET	X2
R1	22kΩ Potentiometer	X1
R2, R3	100Ω 1/4W Resistor	X2
C1	0.22uF Polyester Flim Capacitor	X1
D1, D2	UF4007 Ultrafast Diode	X2
T1	12V 5A Center-tapped Transformer	X1

Circuit Diagram

The schematic of a 60-watt square wave inverter circuit is shown below.

Circuit Explanation

The operating voltage is 12V DC. The IC CD4047 is configured as an Astable Multivibrator to generate a square wave output at approximately 50Hz, determined by external components R1 and C1.

The formula to determine the frequency (f) is: f = 1/(4.4 x R1 x C1)

The IC U1 provides two outputs (Q and Q’) that are 180 degrees out of phase, meaning when one is high, the other is low. These outputs control two MOSFETs (Q1 and Q2) via resistors R2 and R3. The flyback diodes (D1, D2) are used with the MOSFETs to protect them from voltage spikes generated when the transformer's primary winding is switched off.

When Q (pin 10) is high, Q1 conducts, allowing current to flow from the T1 transformer's center tapped through one half of the primary winding, creating a magnetic field. When Q’ (pin 11) is high, Q2 conducts, allowing current to flow from the center tapped of the transformer through the other half of the primary winding to ground.

This alternating switching induces a 220V AC square wave output at 50Hz across the transformer's secondary winding, suitable for powering AC loads that can tolerate square wave input.