Hello Friends,
I've been trying to make an AC fan regulator that can be controlled electronically using a controller. I have already detected the zero crossing perfectly using 4n35 optocoupler. I've seen the pulses on the digital oscilloscope too. I saw the rectified wave and zero crossing pulses together and they are perfect. I also achieved shifting of the pulses as per the count entered. But when I use the triac circuit attached here, it works perfect at full speed but doesnt work at lower speeds.
I dont understand where the trouble is. The wave supplied to the fan is perfect at full speed but it get highly distorted at any other speed value.
MOC3041 has inbuilt zero crossing detor ckt. it'll trigger the TRIAC when the supply crossing zero (zero volt switching). If u r trying for phase angle contro method u need to use MOC3021.
if a opto diac module has inbuilt zero crossing detector it'll trigger TRIAC only when it crosses zero even u give trigger command at any position of the phase ex 90 deg
but if it doesn't have zero crossing detector it'll trigger the TRIAC immediately at the same instant of the LED I/P which u r giving.
I hope with the following waveform u can understand easily MOC3021
MOC3041 has inbuilt zero crossing detor ckt. it'll trigger the TRIAC when the supply crossing zero (zero volt switching). If u r trying for phase angle contro method u need to use MOC3021.
8.2K is very high value that's what I think. reduce it to lesser value. have a look at my previous post (quoted here)
try this ckt. I used MOC3021 with BT136. It worked well.
first try with 90 deg firing angle. because if ur zero crossing gives pulse before zerocrossing then ur conroller may trigger at wrong undesired position. so at first try to fire at 90 deg. so that more time gap will be tre. if u get proper result for 90 deg then goahead with different firing angle.
8.2K is very high value that's what I think. reduce it to lesser value. have a look at my previous post (quoted here)
try this ckt. I used MOC3021 with BT136. It worked well.
first try with 90 deg firing angle. because if ur zero crossing gives pulse before zerocrossing then ur conroller may trigger at wrong undesired position. so at first try to fire at 90 deg. so that more time gap will be tre. if u get proper result for 90 deg then goahead with different firing angle.
I dimmed a bulb finally with just change in optocoupler.Its moc3021. Will look now for the heating problem. Currently i have a small heat sink only. So will try and achieve success somehow....keep helping...
I dimmed a bulb finally with just change in optocoupler.Its moc3021. Will look now for the heating problem. Currently i have a small heat sink only. So will try and achieve success somehow....keep helping...
Hey dude,need help once again. I dimmed the fan too easily but the problem is that the fan turns off if I trigger after the first half of positive half cycle of voltage. Seems like it is because of current lag as fan is inductive load.....so I have set 5 steps in the first half of the cycle only. But when the fan is at a slower speed, it makes minor noise as if its connected to an impure sine wave.The sound is like the one that comes when an inverter is connected to the supply.