Author Topic: Resistor Identification Help Please  (Read 2772 times)

PaulF

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Resistor Identification Help Please
« on: 18 June, 2020, 03:17:45 pm »
As a lockdown project I'm building a phaser* :o   from a kit. I'm trying to reconcile the parts list and can't match all the resistors. It may be my aging eyes but could someone (Kim I'm looking at you :) ) confirm my identification of the resistors in the image.








*guitar effect rather than Star Trek

Re: Resistor Identification Help Please
« Reply #1 on: 18 June, 2020, 03:36:59 pm »
As a lockdown project I'm building a phaser* :o   from a kit. I'm trying to reconcile the parts list and can't match all the resistors. It may be my aging eyes but could someone (Kim I'm looking at you :) ) confirm my identification of the resistors in the image.








*guitar effect rather than Star Trek
I'm guessing that you're not in possession of a multimeter?  From those that have markings that are legible you have the values correct, but there are some that are too murky for my eyes.
Most of the stuff I say is true because I saw it in a dream and I don't have the presence of mind to make up lies when I'm asleep.   Bryan Andreas

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: Resistor Identification Help Please
« Reply #2 on: 18 June, 2020, 03:55:48 pm »
Thanks

Sadly my "multimeter" is limited to voltage and continuity, but it sounds like a good idea for this project so I've ordered one :thumbsup:

Karla

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Re: Resistor Identification Help Please
« Reply #3 on: 18 June, 2020, 04:02:39 pm »
You know that Kim is colourblind, right? 

Anyway, welcome to the world that us colourblind electrickers have to deal with every day.  There are two solutions to your problem:

1) Measure it with a multimeter
2) Throw it away and get another one from the drawer marked "xxx Ohm resistors"

Kim

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Re: Resistor Identification Help Please
« Reply #4 on: 18 June, 2020, 04:11:14 pm »
^ This.

If you've got a child to punish, you can collect the mixed resistors and get them to sort them back into the correct drawers.  If they've been really bad, don't give them a meter.

(My original reply was going to be "Yep, those are definitely resistors".)

Re: Resistor Identification Help Please
« Reply #5 on: 18 June, 2020, 04:15:57 pm »
So I had a look on my laptop screen with the brightness turned up 8) and would say you've reconciled them correctly, though the last one appears to be 47r as opposed to 57r
Most of the stuff I say is true because I saw it in a dream and I don't have the presence of mind to make up lies when I'm asleep.   Bryan Andreas

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: Resistor Identification Help Please
« Reply #6 on: 18 June, 2020, 04:18:17 pm »
You know that Kim is colourblind, right? 

Anyway, welcome to the world that us colourblind electrickers have to deal with every day.  There are two solutions to your problem:

1) Measure it with a multimeter
2) Throw it away and get another one from the drawer marked "xxx Ohm resistors"

I didn't @Kim my apologies. Multimeter on order

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: Resistor Identification Help Please
« Reply #7 on: 18 June, 2020, 04:20:30 pm »
So I had a look on my laptop screen with the brightness turned up 8) and would say you've reconciled them correctly, though the last one appears to be 47r as opposed to 57r

Thanks - that would make sense as I'm missing a 47r

Kim

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Re: Resistor Identification Help Please
« Reply #8 on: 18 June, 2020, 04:31:01 pm »
For low-faff component-identification (eg. when putting the unused resistors back in the drawers) I can recommend:

a) Dedicate a cheap multimeter (but not so cheap it can't auto-range) with short test leads terminating in crocogator clips.  This eliminates the conductivity of your body when holding high-value resistors against probes.

b) Those gimmicky looking multi-function component testers you can get as kits from ebay, that use a ZIF socket to accept the component legs.  Get one with a case so it doesn't slide around or short out on off-cuts of wire or whatever.  (I also find this surprisingly useful for getting the network addresses of DS18B20 temperature sensors.)

yorkie

  • On top of the Galibier
Re: Resistor Identification Help Please
« Reply #9 on: 18 June, 2020, 05:29:57 pm »
You know that Kim is colourblind, right? 

Anyway, welcome to the world that us colourblind electrickers have to deal with every day.  There are two solutions to your problem:

...
2) Throw it away and get another one from the drawer marked "xxx Ohm resistors"


Also known as the University Lab technique?  ;) ;)
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Karla

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Re: Resistor Identification Help Please
« Reply #10 on: 18 June, 2020, 05:54:57 pm »
Got it in one

yorkie

  • On top of the Galibier
Re: Resistor Identification Help Please
« Reply #11 on: 18 June, 2020, 07:02:21 pm »
I may not have learned much from my Uni lab demonstrators, but...
Born to ride my bike, forced to work! ;)

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British Cycling Regional A Circuit Commissaire
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hellymedic

  • Just do it!
Re: Resistor Identification Help Please
« Reply #12 on: 18 June, 2020, 07:27:19 pm »
Black      0
Brown     1
Red         2
Orange    3
Yellow      4
Green      5
Blue         6
Violet       7
Grey        8
White       9

There are some things that stick in the unforgettory.
Read from left to right. First two bands are digits, followed by number of zeros, followed by tolerance.

Or something.

ian

Re: Resistor Identification Help Please
« Reply #13 on: 18 June, 2020, 07:30:18 pm »
Just admit that it's futile.

Kim

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Re: Resistor Identification Help Please
« Reply #14 on: 18 June, 2020, 08:25:30 pm »
Read from left to right. First two bands are digits, followed by number of zeros, followed by tolerance.

Unless the resistor's upside-down :)

Re: Resistor Identification Help Please
« Reply #15 on: 18 June, 2020, 10:55:53 pm »
Unless the resistor's upside-down :)

Or five band.

Sadly my "multimeter" is limited to voltage and continuity

Connect two resistors in series across a low voltage power source, measure the voltage across each and you have their relative resistances. So all you need is one known resistor and you can work out the rest.

TheLurker

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Re: Resistor Identification Help Please
« Reply #16 on: 19 June, 2020, 06:14:28 am »
Or, if really bored, make yourself a Wheatstone Bridge.
Τα πιο όμορφα ταξίδια γίνονται με τις δικές μας δυνάμεις - Φίλοι του Ποδήλατου

Re: Resistor Identification Help Please
« Reply #17 on: 19 June, 2020, 06:28:55 am »
Or, if really bored, make yourself a Wheatstone Bridge.
That's near Edgware Road, isn't it?

Tim Hall

  • Victoria is my queen
Re: Resistor Identification Help Please
« Reply #18 on: 19 June, 2020, 09:04:51 am »
Or, if really bored, make yourself a Wheatstone Bridge.
That's near Edgware Road, isn't it?
Manor Royal Industrial Estate, Crawley, has a several of roads named after industrial/technical/engineering people. Priestley Way (near the BOC depot,obvs), Fleming Way, Royce Road ect ect. There's a road running toward a railway bridge, called Wheatstone Way. I like to think it's not a coincidence.
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Karla

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Re: Resistor Identification Help Please
« Reply #19 on: 19 June, 2020, 10:36:35 am »
Or, if really bored, make yourself a Wheatstone Bridge.
That's near Edgware Road, isn't it?
Manor Royal Industrial Estate, Crawley, has a several of roads named after industrial/technical/engineering people. Priestley Way (near the BOC depot,obvs), Fleming Way, Royce Road ect ect. There's a road running toward a railway bridge, called Wheatstone Way. I like to think it's not a coincidence.

Do they do Electro-Convulsive Therapy there?

Re: Resistor Identification Help Please
« Reply #20 on: 19 June, 2020, 09:09:40 pm »
The resistor colour code was a Uni challenge  question a while back . The students did not get it.

Feanor

  • It's mostly downhill from here.
Re: Resistor Identification Help Please
« Reply #21 on: 19 June, 2020, 09:20:40 pm »
On most resistors I've bought recently, the colour bands have been very hard to distinguish.
I just read the label on the bag, and/or use the Fluke Multimeter to confirm.

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: Resistor Identification Help Please
« Reply #22 on: 20 June, 2020, 05:34:07 am »
On most resistors I've bought recently, the colour bands have been very hard to distinguish.
I just read the label on the bag, and/or use the Fluke Multimeter to confirm.


Yes, with the advantage of a multimeter, I realise that the thin layer of paint on a blue case was actually yellow and not green.

Kim

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Re: Resistor Identification Help Please
« Reply #23 on: 20 June, 2020, 11:59:15 am »
I find it's a lot harder to see the colours on the blue cased resistors compared to the beige ones.

(I never actually bothered to learn the colour code, other than black being 0 and yellow being 4, because bees.  I've occasionally had to recruit someone with functional eyeballs to decode a component in-situ, at which point I look it up.)

Re: Resistor Identification Help Please
« Reply #24 on: 20 June, 2020, 01:21:41 pm »
I go through intermittent phases of needing use the resistor colour code and tend to forget it -or at least start to doubt my recollection of it- between times. So I have it written out on a piece of paper that sits inside my hobby box of odd resistors.  I have normal colour vision, yet between the fact that the coloured bands are tiny, often dirty, and badly printed, it is often easier to get the multimeter out.

It occurs to me that it should -between digital photography,  and clever software that can identify objects and colours-  be possible to take a photo and have the colour codes read automatically.

cheers