Zero Cross Detector circuit and program using AVR?

[fauzan]

how to make a zero crossing detector circuit using atmega8535? does require a certain program?
I have read the application note, there is written that needed checking program (loops), whether the program really needed?

 

[Tahmid]

Hi,
It depends on the zero cross detector circuit. Of course, you need to write code to detect zero cross, but the amount of code to be written depends on the detector circuit being used.

Have you decided which circuit to use? eg. You could use something like this:
**broken link removed**
or something from **broken link removed**

There are tons of circuits available, both isolated and non-isolated.

Using any of the above circuits, you would require to sense a logic change of state to detect zero crossing. You could use interrupts which would make the sensing better and likely to not be missed.

Use the external interrupts module and INT0, INT1 or INT2.

Hope this helps.
Tahmid.

 

[fauzan]

thank's for your help... do you have any example source about zero cross code in C/C++?

 

[kashif_zealot]

hi tehmid

i used this zero croosing detector for voltage, it is accurate,but i need zero cross detection for load current.. if i use CT then it have two terminals, but this circuit have three terminals.. how i can use it.please help me

 

[Tahmid]

but i need zero cross detection for load current.. if i use CT then it have two terminals, but this circuit have three terminals.. how i can use it.

I didn't get what you are trying to achieve.

 

[kashif_zealot]

i want to detect zero crossing of millivolt sinusoidal signal