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Motor wires? — Parallax Forums

Motor wires?

bubby9534bubby9534 Posts: 36
edited 2012-02-01 11:18 in General Discussion
I am new to electrical engineering so I don't know a lot of stuff about electric parts. I have an electric motor and it has a red, black, and yellow wires. I'm pretty sure red and black are for power (+,-) but what is the yellow wire for?

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2012-01-31 16:26
    It might be a "tachometer". It may provide pulses which correlate to revs.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-01-31 17:44
    Black, red, yellow is a common color combination for motors that use a starter capacitor. Could also be a multispeed synchronous motor. Or...

    Who knows, but without some specs or at least a photo there's no telling what kind of juice the motor expects. There are dozens of types, in all kinds of shapes and sizes.

    -- Gordon
  • idbruceidbruce Posts: 6,197
    edited 2012-01-31 23:10
    bubby9534

    In my opinion, I would imagine that PJ Allen is correct.
    It might be a "tachometer".

    Personal computer fans are a classic black, red, and yellow wire combination. In this instance, the yellow wire is definitely for measuring the RPMs of the fan. So do some reading on computer fans which should result in more knowledge.

    Bruce
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-31 23:22
    While we're guessing, why not a brushless motor? They have three wires.
  • idbruceidbruce Posts: 6,197
    edited 2012-01-31 23:33
    Okay, I now see the light. :) Okay, besides being a brushless motor or having a third wire for monitoring RPM, what are the other possibilities?

    Bruce
  • TymkrsTymkrs Posts: 539
    edited 2012-02-01 01:45
    Well, for rc servos, PWM signal/control?
  • TtailspinTtailspin Posts: 1,326
    edited 2012-02-01 07:07
    The yellow wire is always for the airbag...
  • bubby9534bubby9534 Posts: 36
    edited 2012-02-01 08:09
    Here are pictures
    DSC01247.JPG
    DSC01244.JPG
    DSC01246.JPG
    DSC01247.JPG
    640 x 480 - 38K
    DSC01244.JPG
    640 x 480 - 42K
    DSC01246.JPG
    640 x 480 - 41K
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-02-01 08:18
    It could be a permanent split-capacitor motor, requiring an external cap to run: http://www.allaboutcircuits.com/vol_2/chpt_13/9.html. The cap provides a phase shift for directional control, and the motor can be reversed by switching leads that the cap is connected to.

    It might also be a two-speed motor, commonly used for fans

    -Phil
  • idbruceidbruce Posts: 6,197
    edited 2012-02-01 10:42
    Being a 120V AC motor, well that puts a different SPIN on things. Disregard my previous posts :)
  • bubby9534bubby9534 Posts: 36
    edited 2012-02-01 11:04
    No wonder. Hehheh embarassing (SOLVED)
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-02-01 11:18
    As I suspected, and Phil surmised, an AC motor using an external cap or multispeed taps. I'm betting on the former, given that the motor has an integrated cooling fan and a pulley that appears to have quite a bit of torque wear on it. I'm guessing it's for the evaporator fan on a refrigeration or air conditioning unit -- but that's just a guess. You can determine some things by using a meter on the wires, but peeking inside is best, assuming you can't find it by the model number.

    -- Gordon
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