Re: Project automatic fancontroller based on 2sensor-temp,mo
Hii delfadzli,
You can't Control AC load using PWM, it's diffrent from DC.
First there is 2 methode for controlling AC load (1 Phasa) :
1. Time Proportioning ( this methode is adjust power to load in whole half- cycles. Example for 100% you give 100 half cycle, for 50% you give 50 half cycle)
2. Phase Angle Firing (is adjust time firing for tria after zero crossing).
I've never use time proportioning. But I've already use phase angle firing methode
For Phase Angle firing Methode :
1. You need Zero Crossing Circuit ==> the aim of this circuit is to detect when Vamplitude of the AC signal is Zero.
2. Isolation circuit for firing TRIA ==> you can use MOC 303x (with zero crossing)
Algorithm :
1. Detect Zero Crossing
2. After Detect set time for firing triac
This the sample i've already simulate in Proteus : (please check)
I already tried in real world. For resistive load ( like lamp) it's good, but for inductive load (like motor) it's not really good (the noise was come out from the load)