“Hello everyone! Thank you for stopping by this tutorial on how to build a modified square wave inverter that is capable of delivering 200Watts of power.
This inverter delivers a modified square wave AC signal of exactly 50 Hz. This is possible by using a crystal oscillator which helps us to get super accurate frequencies. Other features of this inverter include:
Waveform shape control and dead time adjustment
Low Voltage cutoff
Precise frequency operation without using microcontroller.
The best thing about this design is that it is free from microcontrollers and complex programming and uses traditionally available PWM control chips, counters, frequency dividers and some smart combination of these classic ICs.
So without further adieu let’s get started!
Since this inverter is different from most DIY classical designs available over the internet so I have made the entire project in parts and have eventually combined all of them to make the final product.
Basically the inverter consists of 3 parts:
DC to DC converter module. It converter the low 12V DC to high voltage till about 300volts. The link to this module, build process details and theory can be found here:
https://www.instructables.com/200Watts-12V-to-220V…
2. DC to AC converter module. It is basically a High voltage H bridge circuit that is capable of converting DC voltage to AC voltage. The link to this module, build process details and theory can be found here:
https://www.instructables.com/220V-DC-to-220V-AC-D..
3. The Modified square wave control module. This is a crystal oscillator controlled TL494 based module that generates the control signals for the MOSFETS of the H bridge. The deadtime and this the waveform can be easily varied using a potentiometer based on requirement. The link to this module, build process details and theory can be found here:
https://www.instructables.com/TL494-Working-With-a…
All these 3 modules come together in this project and make the final intended inverter.”