How to Build a 150W Inverter Using SG3525 and IRF3205 MOSFETs

In this blog post, we will guide you step by step to build a 150W inverter using the SG3525 PWM controller and IRF3205 MOSFETs. This inverter can efficiently convert 12V DC from a battery into 220V AC, which can be used to power household appliances like lights and small fans.

Components Required

✅ Major Components:

1. SG3525 PWM Controller IC
2. IRF3205 MOSFETs (x2)
3. Step-up Transformer (12V-0-12V to 220V, 150W)
4. 18650 Li-ion Battery Pack (12V, 10Ah recommended)
5. Electrolytic Capacitors (2200µF, 16V, and 100µF, 50V)
6. Resistors (1KΩ, 10KΩ, 100Ω, 220Ω)
7. Diodes (1N4007, FR107)
8. Heat Sink for MOSFETs
9. Wires and Connectors
10. PCB or Breadboard for testing

The SG3525 IC generates PWM (Pulse Width Modulation) signals, which are used to drive the IRF3205 MOSFETs. The MOSFETs switch the 12V DC battery power at a high frequency, creating an AC waveform. The step-up transformer then converts this into 220V AC.

🔹 SG3525 generates PWM signals to control the MOSFETs.

🔹 IRF3205/IRFZ44N/75NF75 MOSFETs act as power switches to drive the transformer.

🔹 The step-up transformer converts the 12V AC to 220V AC.

🔹 The output AC is used to power devices like lights and fans.

1. Connect the SG3525 IC with timing resistors and capacitors to set the frequency (~50Hz).
2. Use a 1KΩ resistor to limit the gate current of IRF3205 MOSFETs.
3. Connect a 100Ω resistor at the output for stability.

1. Place the IRF3205 MOSFETs in parallel for higher current handling.
2. Attach a heat sink to prevent overheating.
3. Ensure proper gate drive signals from SG3525.

1. Use a center-tapped transformer (12V-0-12V to 220V AC).
2. Connect MOSFET drains to the primary winding.
3. The secondary winding will output 220V AC.

1. Use a 12V, 10Ah Li-ion battery pack.
2. Add a fuse (10A) and a switch for safety.

1. Connect a multimeter to check voltage levels.
2. Attach a 100W bulb as a test load.
3. Observe proper AC output (220V, 50Hz).