12V DC to 220V AC 35 Watt Inverter Circuit

We will be learning how to construct a basic 12V to 220V 35W inverter circuit in this tutorial. In areas where load shedding is a frequent issue, inverters are frequently required. There are two kinds of inverters: modified inverters, which are less expensive, and sine wave inverters, which are more costly.

Electronic devices are harmed by the square wave pulse that the modified inverter produces in its output. This is the reason why electronic equipment does not use this kind of inverter.

To do this, a simple DC to AC voltage inverter circuit using basic power transistors is developed. This kind of transistor is used as a switching device to convert a 12V DC voltage to an output of single-phase AC (220V).

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Principle Behind 12V DC to 220V AC Inverter Circuit

Every inverter circuit’s basic idea is to apply oscillations across the transformer’s primary coil by increasing current, while also producing oscillations with the supplied DC. Next, a higher voltage is achieved by stepping up this output voltage. The primary and secondary coil turns of the transformer determine the output voltage.

We will use transistors to create an inverter in this post. The highest output that this kind of inverter can provide in the load is 35W, however this can be changed by adding additional MOSFETs. This kind of inverter is employed by gadgets that don’t need pure AC. due to the fact that signals from this kind of inverter are not pure sine waves.


12V DC To 220V AC 35W Inverter Circuit

Circuit Schematic



  • 12V-220V Center Tapped Step-Down Transformer
  • 2N2222 Transistors (x2)
  • MOSFET IRF630 (x2)
  • (C1, C2) 2.2uF/60V Capacitors (x2)
  • (R1, R4) Resistor 680Ω (x2)
  • (R2, R3) Register 12KΩ (x2)
  • 12V Battery

Circuit Connection

From the transformer, we connected each component in turn. One end of the transformer’s input is linked to the MOSFET Q1’s drain, while the other end is connected to the MOSFET Q2’s drain. C1 is connected to Q1’s gate terminal, while C2 is connected to Q2’s gate terminal. The R2 and R3 are connected to the other ends of C1 and C2, respectively. These are additionally linked to the transformer’s centre and the battery’s positive supply.

The emitters of transistors Q3 and Q4, which are shorted to one another, are linked to the source terminals of Q1 and Q2, respectively. Q3 and Q4’s base terminals are linked to R3 and R2. The Q3 and Q4 collectors were connected to the R1 and R4, respectively. Additionally connected to the transformer’s centre and positive supply are the R1 and R4. Next, we connect the 12V battery between the emitters of Q3 and Q4 (-V) and the transformer’s centre (+V). We have now finished connecting this 35W inverter.

Working Principle of 12V DC to 220V AC inverter

We must separate this inverter circuit’s operation into three components. A 50Hz oscillator circuit in the first section generates an AC signal with a frequency of 50Hz. An amplifier circuit that amplifies the AC output is the second component. The transformer is the final component.

We need to build an astable multivibrator that generates a 50Hz frequency in order to achieve the oscillation. The oscillator in the circuit is made up of the transistors Q3 and Q4, the capacitors C1, C2, and the resistors R1, R2, R3, and R4.

Inverting square waves are produced by the transistors (Q3 and Q4). The circuit has fixed values for R3, R4, and C2. The frequency changes based on R1, R2, and C1 values.

The formula of the frequency is: F = 1 / (1.38 × R2 × C1)

The formula indicates that the frequency will decrease and vice versa if we select larger values for R2 and C1.

The system then moves on to the amplifier circuit, which is the second stage. The oscillator’s output signal is amplified by the amplifier. It is the power MOSFETs Q1 and Q2 that provide this amplification.

After that, it is linked to a step-down transformer that converts it from 12 V DC to 220 AC via a central tap.

To convert 12 volts to 220 volts, the transformer’s main and secondary coil ratios must be 1:19. The maximum 35W is supported by this type.

Make use of a 24V battery and increase the number of MOSFETs in the inverter to boost its capacity.

Applications of 12V DC to 220V AC Inverter

  • Mobile Power Source: Using a 12V battery to power AC items (such as laptops, chargers, or small appliances) in off-grid or mobile environments, such as on camping trips or other isolated locales.
  • Emergency Power Supply: During power cuts, this backup power enables necessary equipment like fans, lights, and communication devices to continue operating even when the primary power supply isn’t accessible.
  • Solar Power Systems: combining batteries and solar panels to build independent power systems that let regular home appliances be used in off-grid areas.
  • Remote Monitoring Stations: Providing electricity to data loggers, sensor systems, and other remote monitoring devices in places without grid connection.
  • DIY Projects and Hobbies: Including the inverter circuit in any experiments, hobbies, or DIY projects that call for AC-powered equipment.

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