[PIC] PIC16f877a PWM interface using a bulb with in-build zero crossing optocoupler

[bhoobalan]

Hello friends,
I am doing one simple project which controls the brightness of the bulb, I have PIC16F877A micro-controller,MOC3031 in-build zero crossing detector,bulb i am using is 25 watt,Triac,LED,Alternator.
I am using 120Hz for the bulb(PWM) and the device operating frequency is 12MHz.
I am using MPLABxIDE xc8 compiler and the simulator is proteus. I have attached my circuit diagram with code.
I am controlling the brightness of the bulb using PWM,i got the output but it is not working fine,
the output bulb get flickers frequently. When i check the voltage in that point it continuously changing from 0 to 200 v. And i can't able to see the changes in the brightness.
This is the problem i am facing. Tell me that how to avoid the flickering of the bulb and how to get constant voltage?

Pls help me friends reply me with in today because i need to submit this immediately

Thanks in advance

 

[D.A.(Tony)Stewart]

For 220Vac you should be using MOC304x not MOC303x

What range of control causes flicker? < 10%?
Does adding 330R across Triac gate to MT2 help?
Triac should not be grounded! That defeats safety isolation.

Flicker is usually caused by nonlinear lamp load and unequal trigger current in Triac quadrants. Which triac?

 

[bhoobalan]

Thanks for your reply Sunnyskyguy,
My circuit diagram itself contains the required information.
Did you cross checked my code?

Flickering occurs in the range below 0-70% after that there is no flickering from 70-100%.
Triac is A1A2G.

 

[FvM]

I neither understand the circuit nor the software.

A ZCD opto triac is good for on-off control, not lamp brightness control. You'll use non-ZCD optotriac and phase angle control. A zero-crossing reference input must be feed by the AC supply. Review edaboard threads about PIC lamp dimmer.