PWM Inverter Circuit

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Introduction

Electronics and electrical engineering underwent a revolution with the development of inverters. The invention of the inverter ushers in a new era of solar panel electricity generation. In electricity generation nowadays, the inverter is the primary controlling device. Therefore, this tutorial will cover the “PWM Inverter Circuit.”

Inverters employ pulse width modulation, or PWM, technology to provide a constant AC output voltage of 230V or 110V regardless of the load. The PWM-based inverters are more advanced than the traditional inverters. These inverters are perfect for all sorts of loads due to the usage of MOSFETs in the circuit.

Hardware Required

S.no	Component	Value	Qty
1.	IC	SG3524	1
2.	Transformer	12v-0-12v	1
3.	MOSFET	IRFZ44N	4
4.	Schottky Diode	SB5200	1
5.	Ceramic Capacitor	0.001uF, 0.1uF, 100nF	1, 2, 2
6.	Electrolytic Capacitor	1uF, 100uF	1,
7.	Resistor	22Ω, 56Ω, 200Ω, 1KΩ, 4.7KΩ, 10KΩ, 20K, 22KΩ, 100KΩ	4, 2, 1, 3, 2, 1, 1, 1, 2
8.	Battery	12V	1
9.	2-Pin Connector	–	1

Circuit Diagram

Working Explanation

This PWM inverter circuit contains three stages:

Switching pulse generator
Switching device
Output driver

Switching Pulse Generator

The switching pulse generator is a significant stage in producing PWM pulses following the sine wave reference. The RT and CT element values of the IC SG3524 produce fixed-frequency PWM, which can be changed.

Therefore we can estimate the fixed frequency with the formula:

f= 1.30/ (RT) (CT)

Switching Device

The output from the IC pins Emit1 and Emit2 is directly fed into the switching device, which comprises an N-channel MOSFET (IRFZ44). Emit1 is driving the transistors Q1 and Q2. Emit2 output from the SG3524 drives MOSFETs Q3 and Q4.

Output Driver

A transformer with a current rating of 2 A is used in the step-up output driver to increase the output voltage. The tiny circuit collects sample output and provides reference feedback to the PWM regulator.