Identifying resistor value

Discussion in 'General Electronics Chat' started by Clytle374, Sep 21, 2015.

  1. Clytle374

    Thread Starter New Member

    Sep 21, 2015
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    So this is a 2 watt resistor. I can't seem to get the color codes to work out.

    A wire shorted to ground burning it, and a pot, up. I am going to have to replace the pot by trial and error. Not having a full resistor set in 2 watts, and having 2 variables... I need to figure this out.
     
  2. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    Try another picture, with your light source originating from the un-burned side... Your colors are indecipherable.
     
  3. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    I see 47 ohms 5%.
     
  4. Clytle374

    Thread Starter New Member

    Sep 21, 2015
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    Sorry colors are
    Yellow gold green violet Yellow

    Thanks, I wanted to be sure. Doesn’t seem to add up exactly
     
  5. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    I think you are reading it backwards. So, yellow-violet-green would be 4.7 Mohms. Not likely to fry under almost any condition unless dielectric breakdown occurred. Are you sure the middle band is green and not black?
     
  6. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    If green, and a 5 band resistor, then
    Yellow. 4
    Violet. 7
    Green. 5
    Gold. X0.1 multiplier
    Yellow +/- 4% tolerance.

    I would say 47.5 ohms.



    If black, it would be 47.0 ohms.


    Yellow is not a common tolerance band but, it is old looking and may have been popular at one time.
     
  7. Clytle374

    Thread Starter New Member

    Sep 21, 2015
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    Well I feel a lot better now that it is a little confusing. The middle band has a green tent and looks like it cooked darker. But .5 Ohms seems unlikely and pointless so maybe the heat, or age added the green tent.

    It is from the 70s I think. Someone replaced a wire on a pot, and allowed it to short to ground. I will go with 47 ohms and then start with a large value pot and see what happens... No schematics or parts are available for it.

    Thanks
    Cory
     
  8. #12

    Expert

    Nov 30, 2010
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    How many ohms in the pot?
    (Placing 47 ohms in series with a 100k pot simply doesn't make sense.)
    With a 2 watt rating, we would assume the resistor uses up most of the voltage because most pots are about 1/2 watt.
    Assuming the resistor really needed to dissipate one watt, the pot should be vaguely 20% of the total resistance in that circuit.

    Not a real answer, but a method to "ballpark" the value.
     
  9. Clytle374

    Thread Starter New Member

    Sep 21, 2015
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    Well the pot is burnt up and is old enough that the pot manufacturer doesn't have records of it. There are several things tied together at the control panel, and honestly the resistor being in line with the pot was just a guess.

    I knew I needed those 2 parts just to give it a try, will be looking into it more next week.
     
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