Variable speed controller for 240Vac ceiling fan - Electronic Circuits Projects Diagrams Free

Chin · 2nd May 2005, 04:21 AM

I have a ceiling fan using a 3 step (speed) transformer type of control.I am thinking to build an electronics stepless variable speed control. Is it possible to use the dimmer circuit using Triac for lighting? I wonder if the dimmer circuit will be able to withstand the feedback current when we initially turn on the fan. Any suggestion is appreciated.
Thanks

Chin

ljcox · 2nd May 2005, 05:07 AM

I doubt wheter a light dimmer will be suitable. As you said, the starting current will be large and I expect that the dimmers are not designed for inductive loads.

Have you done a search of this forum for motor controllers?

Also try internet sites such as www.discovercircuits.com

In particular, se http://www.discovercircuits.com/M/motor-cont.htm

Len

**Nigel Goodwin** · 2nd May 2005, 09:41 AM

Quote:

Originally Posted by Chin

I have a ceiling fan using a 3 step (speed) transformer type of control.I am thinking to build an electronics stepless variable speed control. Is it possible to use the dimmer circuit using Triac for lighting? I wonder if the dimmer circuit will be able to withstand the feedback current when we initially turn on the fan. Any suggestion is appreciated.

Those I've seen are not the right type of motor for doing that, I would stick to the switched speed control - they generally either switch different capacitors or transformer windings.

**mechie** · 2nd May 2005, 09:42 AM

A domestic light dimmer could well be the easiest answer ...
http://www.electro-tech-online.com/v...ghlight=dimmer
http://www.electro-tech-online.com/v...ghlight=dimmer

My dimmer is still controlling the same Vent Axia extractor fan and is STILL running at low speeds, the fan got jammed solid for a week or so and everything survived just fine (found a dead bird wedged under fan blade

ops: )

No guarantees ... but it's an easy experiment to try :wink:

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2nd May 2005, 04:21 AM	(permalink)
Chin	Variable speed controller for 240Vac ceiling fan I have a ceiling fan using a 3 step (speed) transformer type of control.I am thinking to build an electronics stepless variable speed control. Is it possible to use the dimmer circuit using Triac for lighting? I wonder if the dimmer circuit will be able to withstand the feedback current when we initially turn on the fan. Any suggestion is appreciated. Thanks Chin

2nd May 2005, 05:07 AM	(permalink)
ljcox	I doubt wheter a light dimmer will be suitable. As you said, the starting current will be large and I expect that the dimmers are not designed for inductive loads. Have you done a search of this forum for motor controllers? Also try internet sites such as www.discovercircuits.com In particular, se http://www.discovercircuits.com/M/motor-cont.htm Len

2nd May 2005, 09:42 AM	(permalink)
mechie	Motor speed control A domestic light dimmer could well be the easiest answer ... http://www.electro-tech-online.com/v...ghlight=dimmer http://www.electro-tech-online.com/v...ghlight=dimmer My dimmer is still controlling the same Vent Axia extractor fan and is STILL running at low speeds, the fan got jammed solid for a week or so and everything survived just fine (found a dead bird wedged under fan blade ops: ) No guarantees ... but it's an easy experiment to try :wink: __________________ I need a memory upgrade ... My head is full !