zero crossing signal problem

guys guys help me plz...i am making a circuit to control intensity of bulb with only two micro switches. i have decided to simple pwm it form microcontroller and directly fed it to MOC3041 to fir traic. but my fellow guides told me that the buld fill flicker. so use zero detecting signal i dnt much space for circuit to expand.so my question will it work directly without using zero crossing signal i dnt have even have CRO for measure des signals..
the working concept is as follows:
i will use one microswitch for increasing the intensity of bulb and another microswitch for decresing the intesity for dat i plan to use pwm itseld form microcontrller but as above i said flicker prob confuse where to start.

another thing i only want to use controller 2051 or pic16f628 want to make small circuit as in could plz suggets help

i have decided to simple pwm it form microcontroller and directly fed it to MOC3041 to fir traic.

Wrong approach. You can only fire Triac after zero crossing. and zero cross input will take only one input pin not more than that. see if you can expand or modify such that ZC can be incorporated in circuit.

can anybody provide me zero crossing detector circuit which work fine with controller precise and accurate with 220v 50hz circuit

did you try google search?
http://www.google.com/search?q=zero+crossing+detector+circuit&hl=en&client=ubuntu&channel=fs&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=QOhfULa0CY3xrQevzoC4CA&sqi=2&ved=0CBwQsAQ&biw=1364&bih=626

ya i did but confused that which one wil work properly. that y asked if sumbdy alresy knw the woking circuit.

Try this simple detector.

There are many Opto -Isolators you could use, it depends on what is available.

The circuit should work with a range of values,ask here if in doubt.

Remember, the main dropper resister will get hot (maybe very hot) and will be
at mains voltage !!!!

Zero crossing is used for phase shift control not PWM.

thnxs ExperimenterUK....will try...although i making dis one

Interesting circuit.
Let us know how it works out.

Hey guys M controlling light intensity using zero detector through microcontroller 2051 using moc3041 and traic 136

what m doing is as there will zero detecting pulse after every 10ms. so m doing is m jst making moc off for 8ms and on for 2ms by this i m achieving 20% brightness BUT
THE PROBLEM IS BULB IS ACHIEVING 20%BRIGHTNESS BUT ITS KEEP ON FLICKER HERE'S THE SIMPLE CODE FOR TESTING M POSTING KINDLY HELP


#include <REG2051.H>
int i,j,a;
sbit moc=P3^7;
void delay();
void delay(int x)
{
for(i=0;i<100;i++)
for(j=0;j<x;j++)
;
}

void isr(void) interrupt 0
{

moc=1; ///bulb off for 8ms
delay(8);
moc=0; /// bulb on for 2ms
delay(2);
moc=1;
delay(8);
moc=0;
delay(2);

}
void main()
{
EX0 = 1; // Enable EX0 Interrupt
EA = 1; // Enable Global Interrupt Flag
while(1)
{
;
}

}


NOTE= i am using moc3041 and connect in such a way that wen i give low pulse i.e '0' it fires..bulb on..

Are you sure the zero crossing detector is working ?

There is no need (or point) waiting 2mS to turn the triac off.
Once triggered it stays on.
Try this.

void isr(void) interrupt 0
{
delay(8);   
moc=0; // bulb on for rest of half cycle
//add a delay of a few microseconds.
moc=1;  // reset for next half  cycle.. triac stays on.
}

I removed your other thread as it is the same question.