5 Simple DIY Inverter Circuits you can Build at Home

Making a simple DIY inverter circuit is very easy if you have a few transistors (BJTs), MOSFETs or one oscillator IC. The main work of all these circuits is same. They take direct current from battery and change it into alternating current using transformer and some switches.

Different types of circuits are there to make inverter. Some use two transistors to make own pulses, others use MOSFETs or separate ICs to control transformer.

In this article we will check five simple inverter circuits. These use different parts and methods, so you can pick one what you need.

Let us see how these different inverter ideas compare.

Simple Inverter Circuit Using Cross-Coupled Transistors

This is most basic way to make inverter with two power transistors. Both transistors are connected cross-coupled, meaning they switch ON and OFF one by one without any extra oscillator IC.

This design is good for learning how transistor inverter works. It uses very less parts and center-tapped transformer.

If you want to see how this simple transistor switching works, check complete circuit and details here:

Simple Cross-Coupled MOSFET Inverter Circuit

In this circuit, we use MOSFETs instead of normal power transistors for switching. Cross-coupled connection is same, but switching parts are changed to MOSFETs.

MOSFETs are very common in power section because they can handle high current easily if circuit design is correct. This circuit helps to understand how same cross-coupled idea works with MOSFETs.

Read complete circuit here:

Simple Inverter Circuit Using IC 4047

IC 4047 is very useful chip for making inverter oscillator. It gives two square wave outputs from opposite sides to control push-pull inverter stage.

Best thing is we do not need to build extra transistor oscillator to make switching signals. IC 4047 does timing job, and external transistors or MOSFETs handle transformer load.

This is good design if you want inverter using special oscillator IC.

Read complete circuit here:

Simple Inverter Circuits Using CMOS ICs 4049, 4011, 4093 and 4060

We can also make inverter oscillators using different CMOS logic ICs. This article shows ideas using IC 4049, IC 4011, IC 4093 and IC 4060. These ICs can be set up to make timing signals, which can drive external transistor or MOSFET power stage.

Interesting thing is we can try different CMOS ICs to get switching pulses. Every IC has different internal setup and working style. So if you have these CMOS ICs in hand, you can check these designs in detail article.

Read complete circuits here:

Simplest 100 Watt Inverter Using BJT Astable as the Oscillator

This design uses separate BJT astable multivibrator circuit to make switching pulses. These signals are used to run power transistor stage connected to transformer.

Main idea is making oscillator part using normal transistors instead of one oscillator IC. This design is made as simple 100 watt inverter test. But real output power depends on transformer, battery, transistors and how you build it.

You can check full schematic and part details in this article.

Read complete circuit here:

Which Type of Simple Inverter Circuit Should You Choose?

If you are confused which one to select, check this table:

What Should You Check Before Selecting an Inverter?

Before building any inverter, first decide how much output power and battery voltage you need.

For example, small inverter for running small lamp needs different transformer and power stage than inverter for heavy load.

Transformer is also very important. Primary winding must match battery voltage and inverter switching setup. Secondary winding must give correct AC output voltage and current.

We must also check switching frequency, transistor or MOSFET rating, heatsink requirement and battery current.

One more important point is output wave. Most simple circuits here are basic square wave inverters. Do not think they are pure sine wave unless proper filter or SPWM part is added.

Lastly, never select circuit just by seeing big wattage claims. Battery, transformer, switches and wires must handle full load safely.

How to Choose the Right Transformer VA Rating

Many people make mistakes while selecting the transformer for these simple inverters. If you use a small transformer for a heavy load, then it will get very hot and burn out.

For 50 Watt to 100 Watt Output: Use a 9V 0 9V or 12V 0 12V transformer with at least 3 Ampere to 5 Ampere current rating.

For Higher Loads: If you want more power, then you must use heavier wire in the transformer primary winding and bigger MOSFET or transistors on a proper aluminum heatsink.

Matching Primary and Secondary: Always check that primary side matches your battery voltage (like 12V) and the secondary side gives the correct AC voltage according to your country standard, like 220V or 110V.

Common Troubleshooting Tips

If you build the circuit and it is not working, then check these common things first: Check Battery Voltage: Sometimes battery is low or discharged so the oscillator will not start switching.

Check Transistor or MOSFET Pin: Wrong pin connection can instantly destroy transistors or ICs. Double check base, collector, emitter for BJTs, or gate, source, drain for MOSFETs.

Check Oscillator Working: If you are using IC 4047 or CMOS ICs, then check if the timing capacitor and resistor are connected properly to create pulses then. You can check the output pins using a multimeter or small LED.

Transformer Wiring: Make sure the center tap is connected to the positive battery line (or negative depending on the circuit design) and the outer end go to switching devices. Wrong transformer wiring will not produce any AC output.

Important Safety Rule While Testing Inverters

High Voltage Danger: transformer secondary output gives 220V or 110V AC. This voltage can give a severe electric shock or fatal injury. Never touch live transformer output wires with bare hand while the circuit is switched ON.

Use Fuse Protection: Always connect a proper fuse between the battery and the inverter input circuit. If there is a short circuit, then the fuse will blow and save your battery and transistor from burning.

Heatsink is Compulsory: Power transistors like 2N3055 or MOSFETs like IRF540 will get very hot during operation. Always bolt them to a good aluminum heatsink using mica washer and insulating paste.

Conclusion

We can make simple inverter circuits in many ways using normal transistors, MOSFETs and CMOS ICs.

Some designs use cross-coupled transistors for direct switching, while others use IC 4047 or other CMOS ICs for oscillator signals.

These five inverter designs give different options to try basic inverter building.

You can check individual articles for circuit diagrams, parts lists and working details. Select design based on your battery voltage, power need and parts you have.

Always check full circuit and parts rating before connecting battery and transformer. AC output can give heavy shock, so use proper insulation and safety during testing.