Power inverter PWM control with AVR (Proteus simulations)

           HI friends here is the post of how to control Power inverter With PWM technique and PWM is generated from Microcontroller.


            Hope that you have read my earlier post about power inverter design that design was traditional design and every thing was done on analog basis like generating triangular waves, comparing with DC offset via a comparator and finally generating PWM.
         
            It is advisable to read first about triggering a single mosfet with microcontroller than going for a full bridge.

           But suddenly you realize that you are living in modern era where microcontrollers can do a lot of things. I also found in built PWM generator mode of AVR microcontroller and reduced a lot of hardware.

           So what I did is configured AVR microcontroller in fast PWM mode and generated all the gate pulses from microcontroller itself.

Triggering mosfets with avre for inverter design

               Here is the Proteus circuit for inverter design.

     One thing to remember here is AS I HAVE SHOWN SEPARATE POWER  SUPPLIES FOR ALL OPTO-COUPLERS YOU HAVE TO USE THEM IN ACTUAL CIRCUIT ALSO OTHERWISE THE INVERTER WILL NOT WORK PROPERLY.

     And one more thing to remember when actually designing inverter from this circuit is that in Proteus you have a common ground but in actual life Ground Concept is  a bit difficult.. so you have to connect ground of respective power supply to source of respected MOSFET.(because we always have to supply Gate pulse with respect to source)


         you can download proteus isis simulation file from HERE.


Correction:
those who have seen circuit before please note the value of resistors r4,r5,r10,r9  there was a typo the value is 220 ohms instead of 560 ohms written before.
           

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IRF 640 & IRF Z44 triggering with AVR Microcontroller(Proteus Simulation)

I am working with power inverter design for final year project. I am using AVR atmega 8535 microcontroller for triggering MOSFET and PWM control.

I have used PWM of avr to generate pwm according to potentiometer varied.

I started working with IRF 640 Mosfet (That was the only available to nearer electronics shop at that time).

An optocoupler IC MCT2E is used for isolation between low voltage side(Microcontroller) to the high voltage side (MOSFET side load). It is always suggested to do so.

Here is the circuit configuration i have used to trigger MOSFET. 

Power mosfet trigger with avr microcontroller by optocoupler in proteus

But while working with optocoupler it is always desirable to use datasheet very carefully. That was the problem with my earlier configuration I blindly put 330 ohm to input side of optocoupler (obviously for current limiting) as we do with normal LED. so I was having 100 uS delay on output side. But that was not proper configuration  according to the MCT2E datasheet. So after studying datasheet and test circuit given in it i come to know that it is 47 ohm is perfect value. And I was able to reduce the delay upto 5 uS(that was desirable to our case).

Then after some successful experiments I replaced IRF 640 with IRF Z44 which was having higher current carrying capacity than the IRF 640.There would be no change in driving circuit as the both MOSFET are pin to pin compatible and gate pulse requirement for both of them is same.

I have tested the circuit in simulations and hardware.

here is the Proteus ISIS simulation of MOSFET triggering 

 

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