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| resistors with 5 colors with silver as the 3rd color? |
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| bitman:
This is probably covered in all Electrical Engineering classes 1:1 - but since I'm color blind I've always just skipped this chapter after yet another try where I totally fail to tell what colors each band is on a resistor. However, I have a rather large one that my ohm-meter isn't really too precise about. It looks like 0.2ohms but I'm not sure, so I thought well, this is nice and large so I tried to use the color codes. ARGH - sorry, which side is which here? I see what looks like silver in the middle - it's definitely NOT white or gray and no chart I've found shows silver in the middle! I know these large power resistors aren't exactly common, the little ones I can barely see there are color bands, let alone the color and of course with SMD we just look at the code under a magnifying glass and look that up. So I guess this skill is going a bit out of fashion, but I would still like to know from the old-timers here. I took a picture to clarify my "dilemma". First how do you tell which side is "first" and second, am I seeing it right that silver is in the middle - which may explain why I cannot see how the color codes would cover <1ohm resistors ... so maybe my chart just doesn't take into account that some resistors are less than 1 ohm. My quest is to learn so a link to something that explains this would suffice. Thanks! |
| IanB:
Here's the first link that comes up, that I expect you have already looked at: https://www.allaboutcircuits.com/textbook/reference/chpt-2/resistor-color-codes/ If there were four bands, it would look like brown-black-silver with gold tolerance, which would be 0.1 Ω, 5% tolerance. However, the violet band messes that up. So I have no idea. Someone else, perhaps? |
| Richard Crowley:
It looks like you can see the resistance element under the conformal coating. It is quite large and has very few turns. So I would expect that it is a very low-value resistor with a decent power rating, and a low tolerance. |
| Nusa:
It sure looks like a resistor, but consider the possibility it's an inductor or capacitor instead. How old is the equipment it came out of? You can calculate a pretty accurate resistance value using a different method. Put it in a simple test circuit with a voltage source and current-limiting resistor in series and measure both current in the circuit and voltage drop across your mystery item. R=V/I |
| Zero999:
It's not a capacitor, otherwise it would read open circuit, on the meter. 0.1Ω sounds like a reasonable number. You could test it with a constant current source, which can be made with an LM317, a resistor and a >5V power supply. Connect it in series with the resistor, measure both the current (the LM317 has a considerable tolerance) and voltage and work out the resistor's value with Ohm's law. This may not be super accurate, but it'll be better than the low resistance range on a typical meter. http://www.bristolwatch.com/ccs/LM317.htm |
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