Re: how does an electrical motor work?
- From: Jeff Wisnia <jwisnia@xxxxxxxxxxxxxx>
- Date: Thu, 28 Jul 2005 11:27:14 -0400
philip5malin@xxxxxxxxxxx wrote:
My pestal fan is not working. So I decided to junk it and meanwhile also take it apart to investigate. I am puzzled by the electrical wirings so I am asking this question. The elecetrical motor has bushings on 2 sides with 2 wires black and white. This part I understand that the wires brings in electricity and rotate the middle magnet to spin around the outside megnetic coil which is energized by 2 wires +/- AC. The Power cord comes with a white wire that go into the housing, another lead go into a samll box. This box is outside of the cyclindrical housing, it is a small 3cmx3cmx1cm box with 3 small wires black, red, purple ,(box which I can adjust speed). Then another box 1cmx1cmx1cm with 2 wires blue and grey that look like a resistor. So there are total 5 wires that go into the motor housing: black,red, purple, white, gray, blue. I think it only need 2 wires to make a motor spin. What do the other wires do? If I use a voltmeter to test each wire, what should I get if it is normal?
Sorry I can't give you a complete and accurate answer Phillip, but you might as well have asked, "How does a wristwatch work". There are too many variations in motor and system designs for anyone to be able to accurately determine what you've got there.
Unfortunately your command of english isn't sufficient for you to fully and clearly describe what you've got there. I'm guessing english isn't your first language because you state dimensions in metric units. But, my command of languages other than my own makes it impossible for me to describe anything at all other than english, so I'm not putting you down, Philip, you're doing better than I could.
That said, lets see what can be done to satisfy your curiousity.
I don't know what a "pestal fan" is, but a guess would be "pedestal fan", a term usually used to describe a fan with a "tall" floor stand.
You say it has "bushings" on 2 sides". If they really are on the sides, then I think you probably mean "brushes" which would likely make the motor be the type which is called a "universal motor".
Look at Paragraph 1.2 on this page:
http://en.wikipedia.org/wiki/Electric_motor#Universal_motors
You didn't say how many fan speeds the "adjust speed box" gives you. If it's just three (zero-slow-fast) the "resistor" you mention is probably a diode rectifier which, when placed in series with the motor "throws away" half of the electric current, so the motor runs slower.
If there's more than three speeds, then the motor's field winding may have some "taps" in it, which would permit the switch to change the number of field coil turns the current flows through, thus changing the strength of its magnetic field and affecting how "hard it will pull" the motor's rotor and fan blades against air resistance.
Here's another simple page describing how various types of motors work:
http://my.execpc.com/~rhoadley/magacmot.htm
Without a complete wiring diagram of what's in your fan, I wouldn't dare hazard a guess as to where to put a voltmeter's leads or what you'd measure on them.
Keep up the curiousity, Philip. Many of us here probably took apart a family alarm clock when they were young to "see how it worked". (And a lot fewer of us put it back together again so it worked.) That's one way of learning how mechanical and electromechanical systems work. Too bad the same can't be said of electronic technology, you won't get much of a clue about how a microprocessor does its thing by cracking it open.
Jeff
-- Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Truth exists; only falsehood has to be invented." .
- References:
- how does an electrical motor work?
- From: philip5malin
- how does an electrical motor work?
- Prev by Date: Re: attic ventilation
- Next by Date: Re: Spray insulation / insulating foam?
- Previous by thread: Re: how does an electrical motor work?
- Next by thread: Re: how does an electrical motor work?
- Index(es):
Relevant Pages
|
