resistor color problem

Discussion in 'General Electronics Chat' started by chief472, Feb 25, 2013.

  1. chief472

    Thread Starter New Member

    Feb 25, 2013
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    I need some help with the colors on a 2 watt resistor. The colors are Black, Brown, Black, Gold. I didn't think you could have Black as the first color on a resistor so I'm confused.[​IMG] With the color rings I have, I'm reading this as a 1 ohm resistor (0,1,0,5%). I have two of these and they both measure around 34K ohms. Can someone tell me what I'm missing?[​IMG]
     
  2. MrChips

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    Send us a photo.
     
  3. thatoneguy

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    What color is the body? Are they darkened due to heat damage?

    A photo would help greatly, attach with the paperclip icon in the advanced editor.
     
  4. chief472

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    Feb 25, 2013
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    I'm being blocked by the size of the picture I can upload. I can't find a camera that will take a picture smaller than 293kb, the limit for a jpeg file.
     
  5. chief472

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    Feb 25, 2013
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    The body of the resistor is gray. It is a 1 watt resistor not a 2 as I indicated early. On one end of one of the resistors it is darkened, but not on the other one. I have looked at it under magnification and it sure appears to be Black, Brown, Black, Gold.
     
  6. bertus

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  7. chief472

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    Feb 25, 2013
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    This is the best picture I could get.
     
  8. #12

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    So...you are wondering if these resistors are really 1 ohm and got so hot they either changed their resistance or distorted their paint colors.

    What value does the schematic say...or are these just junk box parts that you're trying to sort?

    If they come from something you're fixing, use the value on the schematic.
    If they are just parts you scavenged, throw them out. They've been overheated.
     
  9. thatoneguy

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    Both of these measure the same value? The resistor doesn't seem to have heat damage.

    Try Macro mode on the camera, looking straight down at it, so the field of view covers the size of the resistor. Photo looks like it focused perfectly on the table behind it from the slant angle.

    Another good and small/fast program to view/resize images is Irfanview (odd spelling, but program is awesome and free)

    33k would be the closest standard value, but that's Orange Orange Orange, I'd guess the resistors would show more signs of heat to distort the colors that much. Though the colors due darken a bit. Having them show the same value out of circuit makes it interesting.

    Where are these used in the circuit you took them from? That may give a rough idea of their value.
     
  10. chief472

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    Feb 25, 2013
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    This is about the best picture I could get.
     
  11. #12

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    You only have to hold the camera 2 inches farther from the resistor to get it to focus.
     
  12. chief472

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    Feb 25, 2013
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    These resistors came out of a Ridgid battery charger (drill) from Home Depot. The charger is model R840091. The circuit board is 860231001 02. It is resistor 105, 106. The values are not printed on the board or anywhere else I can find. I cannot find and sheets for either the model number or the circuit board. Therefore I cannot find out what the values are, or what they are supposed to be. All I can find out is what they measure and the color code which do not match.
     
  13. chief472

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    Feb 25, 2013
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    here is a better photograph.
     
  14. #12

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    I see that as a 120. Obviously I have the wrong answer.
     
  15. Neosec

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    Feb 25, 2013
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  16. MrChips

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    Looks like brown-brown-brown to me, 110Ω.
     
  17. Neosec

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    Feb 25, 2013
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    ...And it should read as a short so it's bad at ~30k ohms.
     
  18. thatoneguy

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  19. Neosec

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    My bad. Didn't see the R105 R106 labeling. I was reaching for the Black as the first band and inductor fit. But dead wrong.
     
  20. Neosec

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    Feb 25, 2013
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    Is it safe to assume that at 34k ohms the one watt resistors are bad? open? 34k seems pretty high for a 1 watt resistor in a battery charger. If my math is right you could drop 120 VAC across it and not hit 1/2 watt. If it's bad I'm guessing it got hot. And therefore band color issues. does that follow?
     
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