Voltage control one shot for TRIAC

[sacha11]

I am making a driver circuit for HID lamp(73W) along with an electromagnetic ballast. To keep the lamp power constant I have used a TRIAC. TRIAC is to control the current when lamp voltage is changing. For that I have to make circuit that can measure the lamp voltage and feed it back to timer and timer can be triggered by a zero cross detector.

Now the problem is the timer have to adjust the delay time for one shot after zero cross detector triggers. this delay time is depending on the lamp voltage that can vary between 50 to 130 volt.

Could you please suggest me some solution that how can I feed back the lamp AC voltage to timer and timer can adgust the delay time of one shot that can trigger the TRIAC.

I hope I have cleared the situation enough, but if there is any question you can ask anytime.

Many thanks in advance,
Sacha

 

[IRstuff]

Rather broad question, so A/D and PIC micro for the timing?

TTFN
faq731-376