FAN (220V AC) Speed control
Can someone please help me how to make speed control circuit of AC FAN (220V) of typical household using a DAC controlled by 8051?
Waiting anxiously!!
To vary the speed you have to switch the fan on and off, which is not ideal.
I don't think a DAC will be any use.
This is a simple switching problem and can be done using the same circuit as for
your Light switching question.
There is a project/download that deals with controlling a fan, and at least one
old,long running thread on the subject.
rather there are other things involved in this.. like Zero crossing circuit, Triac firing at zero cross and stuff..
go through this article... it will clear your doubts.
http://www.ubasics.com/adam/electronics/doc/phasecon.shtml
Ajay, actually i am trying to run the Fan using two bits of the microcontroller.
00 > Fan 0ff
01 > Speed 25%
10 > Speed 50%
11 > Max speed
For this i wanted to use the DAC. Do i make any sense?
ExperimenterUK, Can you please kindly post the link for that thread
Ajay, actually i am trying to run the Fan using two bits of the microcontroller.
00 > Fan 0ff
01 > Speed 25%
10 > Speed 50%
11 > Max speed
For this i wanted to use the DAC. Do i make any sense?logistic
It would make sense for simple dc motors, but normal fans don't work that way.
You can't just turn up the voltage to make them run faster.
In fact such motors are not expected to be adjustable.
The best you can do is to pulse them on and off.
Here are the links.
http://www.8051projects.net/downloads170.html
http://www.8051projects.net/forum-t15092-0.html
i can give you idea of generating pwm signal without using in built pwm circuitary nor using adc.
but i am not sure what you want .can u pm me if you need
speed can be varied by different triggereing voltage for the triac ........rajsundar08
In that case a simple DAC can change the voltage at the gate of triac hence changing the speed right?
you dont need a DAC for AC fan control.
rather there are other things involved in this.. like Zero crossing circuit, Triac firing at zero cross and stuff..
go through this article... it will clear your doubts.
http://www.ubasics.com/adam/electronics/doc/phasecon.shtmlAjay Bhargav
I think from this article can solve your problem.
or like ali.mir10v says, you can use PWM to control On Off the fan so you can get any speed of your fan like 20 %, 40%, 65%, etc.
But if your AC fan have 3 button (like i have) , button 1 (for low speed), button 2 (half speed), and button 3 (high speed), you can use Relay for switch the speed changing that button.
[ Edited Thu Jun 25 2009, 04:21 am ]
But if your AC fan have 3 button (like i have) , button 1 (for low speed), button 2 (half speed), and button 3 (high speed), you can use Relay for switch the speed changing that button.Too Payz
I have built a circuit which works with Relays and my 2 bit instructions for 25%, 50% and 100% but it requires three relays and three AC Fan dimmers (ready made from market). I actually wanted to use Triac because relay logic is old and Relays burn easily and have a very small life as compared to Triac.
