sinewave inverter circuit SG3524(PWM)




A 500W PWM inverter circuit built around IC SG3524 is shown here. SG3524 is an integrated switching regulator circuit that has all essential circuitry required for making a switching regulator in single ended or push-pull mode. The built in circuitries inside the SG3524 include pulse width modulator, oscillator, voltage reference, error amplifier, overload protection circuit, output drivers etc. SG3524 forms the heart of this PWM inverter circuit which can correct its output voltage against the variations in the output load. In a non PWM inverter the change in output load directly affects the output voltage (when output load increases output voltage decreases and vice versa), but in a PWM inverter the output voltage remains constant over a range of output load.
CIRCUIT DIAGRAM OF 500W PWM INVERTER.



ABOUT THE CIRCUIT.

Resistor R2 and capacitor C1 sets the frequency of the ICs internal oscillator. Preset R1 can be used for fine tuning of the oscillator frequency. Pin 14 and pin 11 are the emitter terminals of the internal driver transistor of the IC. The             internal driver transistors (pin 13 and 12) are tied together and connected to the +8V rail (output of the 7808). Two 50Hz pulse trains which are 180 degree out of phase are available at pin 14 and 11 of the IC. These are the signals which drive the subsequent power MOSFET stages. When signal at pin 14 is high, MOSFET Q2 is switched ON  and current flows from the +12V source (battery) connected at point a (marked with label a) through the upper half of the transformer (T1) primary and sinks to ground through MOSFET Q3. As a result a voltage is induced in the transformer secondary (due to electromagnetic induction) and this voltage contributes to the upper half cycle of the 240V output waveform. During this period pin 11 will be low and its succeeding stages will be inactive. When 11 of the IC pin goes high MOSFET Q3 is switched ON  and as result Current flows from the +12V source (marked with label a) through the lower half of the transformer primary and sinks to the ground through MOSFET Q2 and the resultant voltage induced at the T2 secondary contributes to the lower half cycle of the 220V output wave form.

The output voltage regulation section of the inverter circuit works as follows. At point ab D2,D3 rectifies this voltage from the centre tapped configuration which   will be proportional to the inverter’s output voltage  is supplied to the pin1 (inverting input of the internal error amplifier of the IC) through R1, R3, R5 and this voltage is compared with the internal reference voltage. This error voltage will be proportional to the variation of the output voltage from the desired value and the IC adjusts the duty cycle of the drive signals ( at pin 14 and 11) in order to bring back the output voltage to the desired value. Preset RV1  can be used for adjusting the inverters output voltage as it directly controls the amount of voltage fed back from the inverter output to the error amplifier section.

U1 and its associated components produce an 8V supply from the 12V source for powering the IC and its related circuitries .C8,9,10   are  filter capacitor to prevent hums from transformer switching . c11 is a filter capacitor wired  parallel to  voltage regulator IC 7808.




25 comments:

  1. I am intrested sir but the numbers of the components in the circuit diagram did not show very well pls email the components and their numbers to me thank you sir.

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  2. U1 is not connected,it should be connected along d2,d3 rail. To see the components clearly click on the image.

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  3. I need the complete circuit .
    Ogbekwetheophilus@gmail.com

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  4. Hello sir. I really need this project. Can u email to me.

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  5. The feedback is not connected or kindly explain where feedback is taken and repost the circuit diagram because the components values are not clear. Thanks for this circuit highly appreciated.

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  6. Can I use n channel musket with this circuit

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  7. Hello can I use n Chanell musfet in this circuit

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  8. The components value cannot be see clearly. Please upload the circuit diagram again.

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  9. It is that same circuit that use the sg3524 ic and the p channel musfet irf4435

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  10. I like your post, but the diagram and number labels are vague when enlarge, hence can not be duplicated and tested. Please repost a clear one. Thank you

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  11. How sine wave is generated. Pl elaborate on this.

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  12. Good write up. Please send me diagram - paobot57@gmail.com

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  13. Pls the number of transistor Q1 in the diagram

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  14. please could you explain how the sinewave was generated.

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  15. Pls which transistor is suitable for Q1, the pnp ?

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  16. Pls which transistor is suitable for Q1, the pnp ?
    My email is :babalolagbenga01@gmail.com

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  17. Thank u so much sir the circuit diagram is work perfectly well I turn it to 24v DC using 7812.
    It power all my appliancee.

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  18. Replies
    1. My email address is olami.opeyemi2019@gmail.com

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  19. Pls sir can I use a smps transformer(ferrite coil) for the circuit.

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  20. does the ic sg3524 consists of dead time control

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  21. hello sir, can i get the complete diagram of the circuit? i really need this for my MTECH project. My email id is - jenifermanta35@gmail.com

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