[Stoves] Variable Speed Stove Fan SIMPLIFIED

[AJH]

On Mon, 04 Dec 2006 22:01:30 +0000, Steve Taylor wrote:

>AJH wrote:
>> That kit Greg posted looks like a Vellerman one. I use a vellerman
>> K8026 to control the motor of a cheap vacuum cleaner (Earlex in UK)
>> that both sucks and blows and have used this on a small crossdraught
>> gasifier type combustor as well as numerous larger burners in
>> converted 205 litre drums and propane cylinders.
>>   
>THAT kit drives universal motors, not DC motors by the way. You'd need 
>to add a rectifier and (ideally) some smoothing capacitors to run the 
>pillar drill DC drive.

Yes the kit I use is a simple dimmer circuit that is able to cope with
a small (3.5amp) inductive load, it supplies a sort of truncated
portion of the sine wave. So it can control the sort of carbon brushed
ac motor in a cheap vacuum cleaner, it also cost a lot less than a dc
controller.

As in my experiments electrical efficiency is not as important as it
would be in the field, with no grid supply, I control my small blower
(a 12V centrifugal fan bought cheaply as a device to blow up air beds
from a cigar lighter socket) by moving a crocodile clip along a length
of nichrome wire I salvaged from an electric heater in a tumble dryer.

AJH