- #1
What is the resistance of this resistor?(pic included)
- Thread starter Jarfi
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- Resistance
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Discussion Overview
The discussion revolves around identifying the resistance value of a resistor based on its color bands. Participants explore methods for interpreting the color code, the significance of the band arrangement, and the challenges faced in reading resistor values accurately.
Discussion Character
- Homework-related
- Technical explanation
- Debate/contested
Main Points Raised
- One participant seeks clarification on which end of the resistor to start counting the color bands to determine the resistance value.
- Another participant provides links to color code charts and suggests that the interpretation of the color bands is left as an exercise for the student.
- Some participants mention that most resistors follow a list of "preferred values," and that recognizing color combinations can become intuitive over time.
- There is a discussion about the significance of the gold band indicating a 5% tolerance and how the arrangement of colors can affect the interpretation of the resistance value.
- One participant expresses uncertainty about whether a certain reflection on the resistor is part of the color bands or not, indicating a lack of clarity in the visual representation.
- Another participant shares their experience with quickly identifying resistance values without needing to read the color bands, but acknowledges difficulties in distinguishing between similar colors under certain lighting conditions.
- There is a suggestion that turning the resistor around was done for the original poster's benefit, implying that experienced individuals may not need to do so.
Areas of Agreement / Disagreement
Participants express varying levels of confidence in reading resistor values, with some sharing intuitive approaches while others highlight the potential for confusion, especially regarding color distinctions. No consensus is reached on the exact resistance value of the resistor in question.
Contextual Notes
Participants note that reflections and discolorations on the resistor may complicate the reading of the color bands, and there is an acknowledgment of the challenges posed by lighting conditions affecting color perception.
- #2
jedishrfu
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Use this chart:
http://www.digikey.com/web export/mkt/general/mkt/resistor-color-chart.jpg
or you can use this website to find out:
http://www.digikey.com/us/en/mkt/4-band-resistors.html
The proof is left to the student...
http://www.digikey.com/web export/mkt/general/mkt/resistor-color-chart.jpg
or you can use this website to find out:
http://www.digikey.com/us/en/mkt/4-band-resistors.html
The proof is left to the student...
- #3
AlephZero
Science Advisor
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Most resistors have values take from a list of "preferred values". A 4-band marking will be from the E24 series, where the "third digit" of the value is always 0. If reading from one end gives a preferred value but from the other end does not, it's a pretty good bet that the preferred value is the correct one.
After a while you get to recognize the color combinations of the preferred values (e.g. yellow-violet = 47) without having the decode the digits one by one.
http://www.logwell.com/tech/components/resistor_values.html
After a while you get to recognize the color combinations of the preferred values (e.g. yellow-violet = 47) without having the decode the digits one by one.
http://www.logwell.com/tech/components/resistor_values.html
- #4
meBigGuy
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The gold at one end of 4 bands says it is a 5% resistor and the 2 value numbers and the multiplier start at the other end.
As stated, sometimes one needs to guess which end based on standard values.
As stated, sometimes one needs to guess which end based on standard values.
- #5
davenn
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well rotating the resistor 180 deg to get the correct orientation you have
or or bk gld gap then tolerance band can't quite make out the colour may be another gold ( 5%)
the 4th band ( gold) indicates a 0.1 Ohm multiplier as per the 1st link in post #2
D
or or bk gld gap then tolerance band can't quite make out the colour may be another gold ( 5%)
the 4th band ( gold) indicates a 0.1 Ohm multiplier as per the 1st link in post #2
D
- #6
meBigGuy
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I didn't think the small reflections and discoloration on the far left were another band. But they could be. (my guess would still be not a band, but it's just that, a guess)
- #7
Baluncore
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When I see an E12 resistor, like an old friend, I instinctively “feel” the resistance value without reading the colour bands.
“gold,blk,org,org” just feels like 33R 5%. There is no need to turn it around to recognise it.
The problem I have is with fluorescent artificial lighting where red and orange look the same.
33k = 2k2 often look the same.
“gold,blk,org,org” just feels like 33R 5%. There is no need to turn it around to recognise it.
The problem I have is with fluorescent artificial lighting where red and orange look the same.
33k = 2k2 often look the same.
- #8
davenn
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baluncore said:
was only turning it around for the OP's sake who is obviously not familiar with reading resistors.
All others, like you and me who are skilled with such ... obviously NO NEED !
if that isn't a far end tolerance band then yes it would be a 33R 5%
Dave