In this tutorial we will learn about easy inverter circuits.
Anyone can understand and build it.
Only few parts are needed with no IC and no complex design.
Just two power transistors and a transformer.
It converts 12V battery power into AC supply which is good for beginners and DIY lovers.
Best for learning how inverter works in real life.
Circuit Working:
Parts List:
| Parts Name | Specification | Quantity |
|---|---|---|
| Resistors | 68Ω 1/4 watt | 4 |
| Semiconductors | Transistors 2N3055 | 2 |
| Transistors MJ2955 | 2 | |
| Battery 12V | 1 | |
| Switch ON / OFF | 1 | |
| Transformer 12V-0V-12V Primary, 120V/220V Secondary | 1 |
The above circuit is for Inverter Circuit using Transistors 2N3055 uses 12V battery as power source.
Two 2N3055 transistors work in push-pull mode and small driver section makes square wave signal.
This signal switches the 2N3055 transistors ON and OFF one by one.
When one transistor turns ON then current flows through one side of transformer primary.
When it turns OFF then the other transistor works.
Transformer changes 12V DC switching into 220V or 120V AC output.
This circuit is simple and gives good power with proper heat sink.
This above circuit is for Inverter Circuit using Transistors MJ2955 also uses 12V battery.
Two MJ2955 power transistors are used and this circuit is self-oscillating astable multivibrator inverter.
Driver circuit produces square wave pulses.
Pulses switch MJ2955 transistors alternately and this MJ2955 handles high current and drives the transformer primary winding.
Transformer steps up voltage from 12V DC switching to 220V or 120V AC.
Circuit works cooler and smoother compared to small transistors.
This inverter is suitable for continuous use with good cooling.
How to Build:
To build a DIY Inverter Circuit using Transistors follow the below connection steps:
- Gather all the parts as shown in circuit diagram:
Connections for Q1 and Q2 2N3055 transistors:
- Emitter to battery negative
- Collector to transformer primary end
- Base to R1 and R2 resistor 68 ohm
- Other end of resistor to opposite collector
Connections for Q1 and Q2 MJ2955 transistors:
- Emitter to battery positive
- Collector to transformer primary end
- Base to R1 and R2 resistor 68 ohm
- Other end of resistor to opposite collector.
Transformer Connection:
- Center tap to battery negative through switch
- Two primary ends to collectors of transistors Q1 and Q2
- Secondary to AC output socket
Conclusion:
This DIY Inverter Circuit using Transistors is very simple.
It is good for learning basic inverter working.
Efficiency is low but acceptable.
Waveform is square wave which is not suitable for sensitive devices.
Best for lights, solder iron and small loads.
Easy to build and we can test at home.
References:
How can I make an inverter circuit with NPN transistors without voltage drop?