3 phase AC Regulator with pic16f877a to save energy in public lighting

[khongyeuem]

I use Rb interrupt(Rb5,Rb6,Rb7) to detect zero crossing of power supply From zero crossing circuit.I want to regulate output voltage provide for lights.You can give me some ideas please?.Thank you very much!!!!

 

[nikhilt007]

make dimmer ckt and use pwm technique for power controlling of light
but here you should care about the type of load if your load ie inductive ,resistive,capacitive
according to that you should write the firm ware and ckt

 

[logicon]

Is your light incandescent or LED? If LED, I suggest you first rectify the scaled-down AC input and power it via DC-DC converter. If incandescent element, you can only rely on a thyristor-controlled PWM converter. The arrangement of the converter depends on the type of load you choose. Click helped me if it helps.

 

[khongyeuem]

I use pic16f877a generate pulse to trigger triac to adjust the brightness of halogen light. 3 phase AC 220/380v.It is light incandescent.Can you help me!!!!!!.I think DC voltage using PWM but AC voltage with triac no using pWM because when trigger triac It will conduct in half cycle .220/380 Ac 50Hz!!!

 

[nikhilt007]

its not like that you have to do trailing edge triggering what you have to do you should set your pwm periode as 10msec and trigger from the trailing edge and vary your pwm duty cycle for getting varying brightness

 

[khongyeuem]

Thank nikhilt007 but such I must use not logic gate to invert pusle from pic16f877a.because duty cycle from zero to 180 degree not from 180 to 0 degree.I regulate for three phase but pic16f877a only have ccp1 and ccp2(pwm1 and pwm2).Can you give me some Idea?

 

[nikhilt007]

instead of using inbuilt pwm you can generate your own soft pwm using only one timer
use three timer for three phase
1)start timer when interrept detect select variable for each timer
and make your out put pin high for suitable duty cycle and make out put pin always low on each interrupt
in this way you can achive i hade done this