Speed controller for bouncy castle fan?

[julianf]

Ive got one of these -

240v AC / 450w


It shifts a lot of air - too much for starting my furnace.

I was going to add dump valves, but its probably way way cheaper just to add a controller.


There are about a million online. Any firm suggestions for something cheap and cheerful?

 

[Wightsparks]

I built one for exactly that motor using this moduie https://www.ebay.co.uk/itm/50-220V-...676318?hash=item2d0920da5e:g:nFIAAOSwhgxemRX7

By "built" I mean I stuck it in a box away from anything flammable just in case!

 

[Fazerruss]

Ive got one of these -

240v AC / 450w


It shifts a lot of air - too much for starting my furnace.

I was going to add dump valves, but its probably way way cheaper just to add a controller.


There are about a million online. Any firm suggestions for something cheap and cheerful?

Is it an induction motor or a universal motor as this will determine if and how to do it?

 

[Hopefuldave]

As long as the motor's separately vented / cooled, you can just put a flap over the blower intake... It'll even hold itself there!

Dave H. (the other one)

 

[julianf]

Is it an induction motor or a universal motor as this will determine if and how to do it?

Don't know. Here is a photo of the actual unit -

These fans are also very cheap - would that give any indication of motor type?

 

[julianf]

As long as the motor's separately vented / cooled, you can just put a flap over the blower intake... It'll even hold itself there!

Dave H. (the other one)

It seems a gate is about £20, whilst a speed controller about £3, and, probably, easier to use. That's my reasoning.


...and with a valve I need additional couplers etc. Like I say, I was considering valves before, and, whilst feasible, it becomes convoluted. Its speed controllers that im interested in now.

 

[eddie49]

Is it an induction motor or a universal motor as this will determine if and how to do it?

Sure to be a Universal motor, so the "light dimmer" type of Triac controller linked to by Wightsparks above will do the job.

 

[vbottles]

It seems a gate is about £20, whilst a speed controller about £3, and, probably, easier to use. That's my reasoning.

Or use a piece of card across the intake. Free. Used a blower like your for bloomery furnace running over 6 hours with no issue and in air force propane forge. If nothing else you can try this until you get a controller.
Andrew

 

[charliecambs]

Sure to be a Universal motor, so the "light dimmer" type of Triac controller linked to by Wightsparks above will do the job.

As far as I know almost all biggish fans are synchronous split phase motors as they run at 1425/2800 rpm where as universal types rely on very high speeds ( maybe 20000 rpm in a corded electric drill).
Split phase ( often no capacitors used) have a lower starting torque than centrifugal switch start synchronous motors so are ideal to "wind up" to speed with a fan where power required increases with fan speed. AC synchronous motor would need a VFD type controller or could use an old school variac.
Think i'd go for a shutter on the intake just beware of overheating as motor air will reduce with speed.

 

[julianf]

Is there any advantage of going for a PWM controller on this sort of thing?

 

[julianf]

I built one for exactly that motor using this moduie https://www.ebay.co.uk/itm/50-220V-...676318?hash=item2d0920da5e:g:nFIAAOSwhgxemRX7

By "built" I mean I stuck it in a box away from anything flammable just in case!

And it all works fine for you? Any irritations?

 

[julianf]

https://www.ebay.co.uk/itm/2000W-AC...epid=0&hash=item5224819b86:g:7WYAAOSwdIFXxp2H

hmm... item location uk...

 

[eddie49]

Description：
This controller uses novel bi-directional high-power SCR.

Wow, it must have one of those new-fangled "Triac" things in it.

 

[Hopefuldave]

If it's a single phase induction motor you can't use a speed controller effectively, and running it below speed will likely cause the motor to overheat (part of the design of the motor is the back-EMF which opposes the current in the windings, this is proportional to speed of rotation so reducng the speed *increases* the winding current...)

Just put a plate over the intake with a self-tapper into the housing, as long as it has an air intake on the end of the motor! (mine does...)

Dave H. (the other one)

 

[Parm]

It seems a gate is about £20, whilst a speed controller about £3, and, probably, easier to use. That's my reasoning.


...and with a valve I need additional couplers etc. Like I say, I was considering valves before, and, whilst feasible, it becomes convoluted. Its speed controllers that im interested in now.

I would go for a speed controller.

Introducing a gate will act as an orifice plate to some extent and interfere with the air flow and static pressure