Programmable fan controller for 240Volt AC 100Watt fan

[drep]

Circuit for solid state relays fan speed control

I am seeking a proven circuit using electro or mechanical or solid state relays that can vary the speed of the fan in steps say about 20 speeds. The fan is 240 Volt 50Hz AC 100 watts, 2400 RPM
A good almost noiseless switching circuit is essential and so is low cost.
I have been told that some motors with a lot of steel built in to the rotor are likely to be less noisy when speed is changed.
Recomendations for a suitable noiseless ducting type fan motor make would also be appreciated.

 

[Boncuk]

To reduce or avoid a noisy motor you should use a zero crossing unit to fire the triac. Also a snubber circuit is a must.

To control speed with 20 steps you don't have much to play with. The fan requires about 110V to start without problems.

I'm using an ATtiny2313 with no noise off the motor.

Boncuk

 

[drep]

Thanks for your reply, what type of fan motor , model, cfm output , watt and make are you using?

 

[drep]

Thanks for your reply, what type of fan motor , model, cfm output , watt and make are you using?

 

[Boncuk]

Hi drep,

I have no idea about brand name. I purchased the fans at "Amorn Shop" in Thailand. They are most probably chinese products.

I estimate an air flow of 2,000cubicmeters/hour at a fan total pressure of 150Pa.

They were noisy at low rpm when connected to a commercial light dimmer, but whisper when connected to my circuit.

My circuit has been tested up to 2.5KW with no malfunction (misfire etc.)

One remark concerning motor control: If the motor is started at e.g. 110V it will continue running at 80V when it has gained rpm. My evaporative cooler makes use of that kind of control by cutting back power after one second. (Motor is a three speed type MCU controlled)

Boncuk