This IC SG3525 Inverter Circuit using IRFZ44 MOSFETs tell us how to make one converter using special chip called SG3525 and parts name MOSFETs.
It changes car battery power 12V DC into 220V AC which is good for using outside.
It uses new idea call pulse width modulation (PWM) to make AC power.
This converter can power normal home things or system using sun power like solar panel.
WARNING: Making high voltage things is dangerous.
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 kind of PWM controller.
It is mostly used in inverter circuit to control switching of power transistor like MOSFET or IGBT.
The IRFZ44 IC is mostly used as power MOSFET in inverter work.
Below is steps how it work and how to make simple SG3525 inverter circuit using IRFZ44 MOSFETs.
Circuit Working:
Parts List:
| Category | Component | 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.
The power must be in safe range as told in SG3525 datasheet.
How SG3525 Work:
Pin 1 and Pin 2 connects to error amplifier inside IC.
This error amplifier compare inside voltage (reference) and outside output voltage which then makes an error signal.
PWM frequency is set by timing resistor RT and timing capacitor CT.
One oscillator inside make clock signal and this clock set switching speed of PWM.
Control part inside IC make PWM signal using clock and error signal and duty cycle is also controlled here.
IRFZ44 MOSFET is used which connects on low side and driven by totem pole circuit in SG3525.
Pin 10 is shutdown pin if low PWM is ON and If high then PWM stop fast.
PWM Output:
Pin 11 and Pin 14 are output pins and they send signal to MOSFET gate.
MOSFET act like power switch to turn ON and OFF fast and this changes DC to AC using PWM.
Filter Section:
PWM output connects to filter part it has coil inductor and capacitor.
This filter clean PWM wave and make it more like sine AC wave.
Power Transformer:
Transformer with 9-0-9V setup is used which increases voltage to make AC output strong.
Results:
At the end we get AC output and this can be used 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.
- When making circuit keep in mind it is PWM inverter using SG3525.
- Give 12V DC power to SG3525 IC.
- Be sure power is in right range as in datasheet.
- To keep VCC voltage stable use voltage regulator.
- Connect Pin 1 and Pin 2 of SG3525 to error amplifier part of circuit.
- Connect RT timing resistor and CT timing capacitor to set PWM frequency.
- Use extra resistor RD to set dead time.
- Connect soft start capacitor from pin 8 to ground.
- Use inside Totem Pole Circuit to drive low side MOSFETs.
- Connect IRFZ44 MOSFET to SG3525 output to do power switching.
- Connect pin 11 and pin 14 of SG3525 to gate of MOSFET.
- Use filter circuit (coil + capacitor) to smooth PWM output.
- Connect IRFZ44 for getting 220V AC output.
- For right pin wiring always check SG3525 datasheet.
- Use power transformer with 10A rating and 9-0-9V type.
- Carefully build full circuit on PCB board.
- Keep space between parts to avoid short circuit an protect parts nicely.
- Fix heat sink to MOSFET to stop overheating.
Testing:
- After turning ON check inverter is working fine.
- Use oscilloscope to see output voltage shape and frequency.
- Be sure inverter can handle up to 300W load without overheating or problem.
Conclusion:
One person can make IC SG3525 Inverter Circuit using IRFZ44 MOSFETs by following these steps and using given formula.
For good working choose all parts and components carefully.
References:
Design of a single-phase power inverter with voltage controller using IC SG3525