Ds1820 -> pid -> pwm

[aratti]

Working with ac and resistive load, phase angle control is the choice (dimmer principle), PWM works very well only with dc.

Since you will have 50 Hz main, every half cycle will last 10 millisecs, so once you have found the zero crossing moment, you will fire your triac with a delay from 0 millisecs to max 10 millisecs.

where:

0 millisecs delay = 100% duty
.
.
5 millisecs delay = 50% duty
.
.
10 millisecs delay = 0 % duty

Remember that your triac will turn off at every zero crossing, which make phase angle control a rather efficient and easy way to control resistive loads with ac.

Cheers

Al.