To begin with, this IC SG3525 Inverter Circuit using IRFZ44 MOSFETs tell us how to make one converter using special chip called SG3525 and parts name MOSFETs.
Also, it changes car battery power 12V DC into 220V AC which is good for using outside and it uses new idea call pulse width modulation (PWM) to make AC power.
Moreover, this converter can power normal home things or system using sun power like solar panel.
WARNING: However, making high voltage things is dangerous, so only try if big person or adult is there to help.
What is a IC SG3525 Inverter Circuit using IRFZ44 MOSFETs:
The SG3525 IC is one type of PWM controller and it mostly works in inverter circuits to control switching of power transistors like MOSFET or IGBT.
First, IRFZ44 works as power MOSFET in inverter circuit and then, below steps show how it works and how to make simple SG3525 inverter circuit using IRFZ44 MOSFETs.
Circuit Working:

Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistors | 10k 1/4W CFR | 6 |
| 10Ω 1/4W CFR | 2 | |
| 47Ω 1/4W CFR | 1 | |
| 50k Preset | 1 | |
| Capacitors | PPC 100nF Capacitor | 1 |
| Electrolytic 1μF Capacitor | 2 | |
| Semiconductors | SG3525 IC | 1 |
| IRFZ44 MOSFET | 2 | |
| Transformer as per diagram | 1 | |
| 12V Battery | 1 |
Power Supply:
The circuit start with 12V DC battery and this power connects to SG3525 IC and the power must be in safe range as told in SG3525 datasheet.
How SG3525 Work:
Pin 1 and pin 2 connect to error amplifier inside IC and this error amplifier compares internal reference voltage with external output voltage, then it makes error signal.
PWM frequency depends on timing resistor RT and timing capacitor CT so they set switching speed.
First, one oscillator inside makes clock signal and this clock sets switching speed of PWM and then control part inside IC makes PWM signal by using clock and error signal and it also controls duty cycle here.
In addition, IRFZ44 MOSFET connects on low side and SG3525 totem pole circuit drives it.
And pin 10 is shutdown pin if low PWM is ON and If high then PWM stop fast.
PWM Output:
Also, pin 11 and Pin 14 are output pins and they send signal to MOSFET gate and MOSFET act like power switch to turn ON and OFF fast and this changes DC to AC using PWM.
Filter Section:
Further, PWM output connects to filter part it has coil inductor and capacitor and this filter clean PWM wave and make it more like sine AC wave.
Power Transformer:
We use a transformer with 9-0-9V setup, which increases voltage and makes AC output strong.
Results:
At the end, we get AC output and we can use it to run normal AC devices.
Formulas:
Oscillator Frequency Formula for SG3525:
We can use this formula to find frequency (f) of SG3525 PWM:
f = 1 / (0.693 × (RT × CT + RD × CT))
where:
- RT is the timing resistor from 2kΩ to 150kΩ
- CT is the timing capacitor from 1nF to 0.2µF
- RD is the dead time resistor
- 0.693 is a fixed value inside SG3525 which helps to calculate correct frequency.
- RT is outside resistor and it connects from pin 6 to ground.
- CT is outside capacitor and it connect from pin 5 to ground.
How to Build:
Below steps are to build a IC SG3525 Inverter Circuit using IRFZ44 MOSFETs:
- First, read SG3525 datasheet to understand pin setup and how it works.
- Next, when making circuit keep in mind it is PWM inverter using SG3525 which give 12V DC power to SG3525 IC.
- Always be sure power is in right range as in datasheet and to keep VCC voltage stable use voltage regulator.
- After that, connect pin 1 and pin 2 of SG3525 to error amplifier part of circuit.
- Then connect RT timing resistor and CT timing capacitor to set PWM frequency.
- Also, use extra resistor RD to set dead time.
- Then connect soft start capacitor from pin 8 to ground and use inside Totem Pole Circuit to drive low side MOSFETs.
- After that connect IRFZ44 MOSFET to SG3525 output to do power switching.
- Next, connect pin 11 and pin 14 of SG3525 to gate of MOSFET.
- And use filter circuit (coil + capacitor) to smooth PWM output.
- Then connect IRFZ44 for getting 220V AC output and for right pin wiring always check SG3525 datasheet.
- Also, use power transformer with 10A rating and 9-0-9V type.
- And carefully build full circuit on PCB board and keep space between parts to avoid short circuit an protect parts nicely.
- Remember to fix heat sink to MOSFET to stop overheating.
Testing:
- After turning ON check inverter is working fine and use oscilloscope to see output voltage shape and frequency.
- Always be sure inverter can handle up to 300W load without overheating or problem.
Conclusion:
To conclude, one person can make IC SG3525 Inverter Circuit using IRFZ44 MOSFETs by following these steps and using given formula.
Also, for good working choose all parts and components carefully.