Please help me on 3-phaseAC voltage Regulator withpic16f877a

[khongyeuem]

I use Zero crossing detect circuit to detect zero point of source voltage. If single phase then I can do it, I have used interrupt timer to create time delay to trigger triac. But with three phase then I can't do it. I have a idea with using three timers to create time delay and one timer to create width square pulse. Just a pity that there are only 3 pic16f877a timer. Can you help me!!! I use RB interrupt to delect rising edge of fulse when detect point of zero.
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anhyeuem

[Mike Walne]

Start by showing us a schematic of what you are proposing.

Mike

[notbad]

What is the load? Is it a motor or something else?

[temtronic]

We need a lot more details.
some are...
AC ? voltage and frequency are very important to know.
Regulator ? are you trying to control/maintain a specific voltage? if so what Tolerance? 1%, 5%, +-3 volts?
What else does the PIC have to do?

You say you've done the task with single phase power, so either a simple hardware or software solution might work for you. In software, you could have 2 other I/O pins 'follow' the '1st phase' I/O pin, simply by having a function like...

if 1st pin set....delay x..set 2nd pin ..delay x... set 3rd pin delay x.
delay x is the time difference between the phases, something you know, we don't.

Typical frequencies for power are 50Hz, 60Hz, 400Hz, 1000Hz, 20KHz.

hth
jay

[khongyeuem]

I thank you for your interest. I use 220/380v AC voltage with 50HZ Frequency. I use to adjust the brightness of the street lamps (halogen lamps). I use RB interupts of pic16f877a (RB5,RB6,RB7) for detect point of zero of 3 phase. Iwant adjust independently from 0 to 180 degree for each phase. I use ADC value from a potentiometer. When I screwed up potentiometer, the lights each phase brightup and When I screwed down potentiometer, the lights each phase brightdown. I'm sorry because my writting enlish skill is not good!!!!!
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anhyeuem

[Ttelmah]

The lamps are only going to be single phase. Just use three of your single phase designs.