I use a dspic33f that has special drivers that controls three phase inverters in a very easy way with 1ns resolution and control of dead time for high side and down side

It is possible to control the three controls by using the same counter.

As example there is dsPIC33FJ16GS502

Use Codevision software, include delay.h

for 50Hz: T=20 ms=20000 us

60 degree ~ 3333 us

Simply using an ATmega8A and a code like :

while(1)

{

PORTD.0=1; PORTD.1=0; PORTD.2=0; // for 3 top switches of inverter (a,b,c phases)

delay_us(3333);

PORTD.0=?; PORTD.1=?; PORTD.2=?;

delay_us(3333);

PORTD.0=?; PORTD.1=?; PORTD.2=?;

delay_us(3333);

...

}

complete the code

Hi Navidreza, this would work?

Hi0,1,2 are the high side and Lo0,1,2 the low side

//this part would be changed for avrs:

#define Hi0 LATBbits.LATB0

#define Lo0 LATBbits.LATB1

#define Hi1 LATBbits.LATB2

#define Lo1 LATBbits.LATB3

#define Hi3 LATBbits.LATB4

#define Lo3 LATBbits.LATB5

//this should work for all micros

Hi0=Hi1=Hi2=Lo0=Lo1=Lo2=0

while(1)

{

Hi0=1;

delay_us(3233);Hi0=0;delay(100);Lo0=1;//I included 100us but it could be changed.

//There are some H bridge that includes dead time

Hi1=1;

delay_us(3233);Hi1=0;delay(100);Lo1=1;

Hi2=1;

delay_us(3233);Hi2=0;delay(100);Lo2=1;

}

http://www.ecnmag.com/sites/ecnmag.com/files/legacyimages/Half-bridge.jpg

Navidreza and Lopez dear ,how could i change the frequency of these pulses ? Can i use interrupt for changing the time period or the delay time ?

Well the micropic dspic33fj16gs502 has a specific input line that can be used to synchronize the control, there is a lot of code sources in internet, but I think you should prefer to control the ON time.If you states thar 3333us is 100% of the output power you could reduce it to reduce output power. Unfortunately I work with pics not avrs, but I will try to make a standard C that you can adapt:

//this part would be changed for avrs:

#define Hi0 LATBbits.LATB0

#define Lo0 LATBbits.LATB1

#define Hi1 LATBbits.LATB2

#define Lo1 LATBbits.LATB3

#define Hi3 LATBbits.LATB4

#define Lo3 LATBbits.LATB5

#define MAX_TIME 3333 //maximum ON time

#define MAX_ANA_CHANNEL 16000 //maximum allowable analog clhannel

unsigned int read_analog_channel(int channel); //your reading analog routine

int main()

{

int on_time=3233,off_time; //on time in microseonds

//this should work for all micros

Hi0=Hi1=Hi2=Lo0=Lo1=Lo2=0;

while(1)

{

unsigned int ana;//to store analog data

ana=read_analog_channel(0);//I asume that the input analog channel is the channel AN0

if ((ana>MAX_ANA_CHANNEL)&&(on_time>1))

on_time--;

else if (on_time