Fully Variable Speed Control Unit for Lasko 2155A Window Fan

That would have been funny 5 minutes ago. Alarm clock broken? Well, you know what to fix it with at least.

Some small induction motors, particularly if driving a load like a fan, can be made to run at a slower speed by simply decreasing the voltage. As has been mentioned, the usual solid state control removes part of the AC waveform, which may result in motor overheating.

This can be done with a tapped autotransformer or simply with a series resistor(s). A variable resistor of sufficient power rating would give limited stepless speed control.

I have a condenser fan on my refrigerator that the repairman replaced with one that sounded like a jet taking off! I dropped the voltage to about 90 volts and it's been happily and quietly running for the past five years.

You'll never know if your particular motor behaves in this way until you try it. It may run fine at a lower voltage, but not start. In this case you need to insure it's always started with the higher voltage.

I cannot believe how difficult it has been to get technical information for the kind of three speed fan being discussed. I Googled various terms. Without heavy restrictions, millions of hits were made without solid information.

I did find something that showed how to switch from two-pole to four-pole operation on for a single phase induction motor.

I did find an ambiguous description on how to get three (or) more speeds from a universal motor by switching what would be the field winding of a series dc motor. Good fans seem to operate with motors without commutators. I do not know if universal motors are used with fans. I would think induction motors would be more reliable and cheaper.

If someone has good links, please pass them along.

I did get to a catalog posting of a motor controller, offered by Granger. I think it was a variable frequency drive. If so, the output voltage was not reduced at low frequency.

Virg, you're wasting your time. This is crosposted from alt.home.repair which is full of trolls and dangerous idiots. Killfile the loser.

Define dangerous. ;)

BTW, I thought Eddie Lebec was one of yours.

Everybody knows that and that's what I'm trying to explain. Heck, while I write this I have to have a gun in each hand and a knife in the other. But all is okay except for the few who drowned in an adjacent bog.

Variable Frequency power inverter. The basic idea would be like taking a UPS and making the output frequency variable.. The real problem doing thiss is that the design of the motor is such that if you get very far away from 60 Hz with a cheap fan motor it is going to start to heat up. To get around this problem you will need a motor designed for it. We use such motors at work and they are expensive.

Jimmie

Just set your internal fan switch to high and use one of these:

It's very unlikely that this speed controller works with induction motors. Most hand tool motors have brushes.

"Rich." wrote in news: snipped-for-privacy@news2.newsguy.com:

or wire an incandescent lamp dimmer to a duplex outlet,then plug in the fan(on high range). That's how I speed control my fixed speed model 270 Dremel Mototool.

Again. Your dremel is a brushed motor, not an induction motor. What works for a motor with brushes doesn't work on induction motors.

I have slowed things down with a green plug.

Greg

For those that don't understand induction motors. An induction motor is both a trasnformer and a motor. It's really a clever idea that recognizes that both motors and transformers are made of two coils. The speed of the rotor is important in an induction motor so speeds are controlled by the design of the motor. That's why multiple speed induction motors have mutliple sets of stator windings. Which winding you energize determines the speed. And also why messing aorund with the voltage, particularly with controls that simply clip the sine wave doesn't work very well. You can vary the speed by changing the frequency. But only to a point because low frequencies don't work so well with a transformer.

I am virtually certain that a that kind of tool uses a universal motor.

The OP here isn't interested in any information from people who know what they are doing -- he/she/it/they are looking for something which does not exist (a cord mounted VFD control) to try and precisely regulate the speed of a $35 dollar consumer grade window fan...

Let the OP figure it out on his own -- clearly doesn't like being informed that his desired device doesn't exist, or that the fan he wants to control won't work with the controller or that the motors which work with VFD controllers are expensive...

The OP is ignoring all of that and is therefore a troll...

~~ Evan

A ceiling paddle fan is an induction motor. Get a paddle fan speed control, install it in a box along with an outlet and a cord. Like one of these:

Define define! ;-)

Never heard of anyone by that name.

Better buy a fire extinguisher, too.

Film at 11, of the fire department trying to put out the fire and drag his corpse out of the building.