Resistor Value?

[TheKeg]

Hello to everyone,

 

I was just wondering if anyone could help me identify what value these resistors are?

Any assistance would be greatly appreciated.

 

 

[Dagworth]

They are not resistors at all, they are chokes (small coils) 

 

replace with plain wire links, the loco will work perfectly. 
 

Andi

[Pandora]

From your image, a 4-band colour code,  Brown Black Gold Silver which is 10 x 0.1 ohms   ie 1 Ohm with 10% tolerance.

HOWEVER, double check band 3,   is it gold or a discoloured / burnt  yellow? If a discoloured yellow, then 100000 which is 100Kohms  same tolerance

 

https://www.wellpcb.com/resistor-color-codes.html

Edited June 28, 2022 by Pandora

[TheKeg]

1 hour ago, Pandora said:

From your image, a 4-band colour code,  Brown Black Gold Silver which is 10 x 0.1 ohms   ie 1 Ohm with 10% tolerance.

HOWEVER, double check band 3,   is it gold or a discoloured / burnt  yellow? If a discoloured yellow, then 100000 which is 100Kohms  same tolerance

 

https://www.wellpcb.com/resistor-color-codes.html

The colours seem to be as follows -

red - black - gold - silver

That would mean 2 ohm?

 

2 hours ago, Dagworth said:

They are not resistors at all, they are chokes (small coils) 

 

replace with plain wire links, the loco will work perfectly. 
 

Andi

 

Ive never seen, coils with colour coded bands before, but if that’s all they are then I will try that solution.

[Dagworth]

2 hours ago, TheKeg said:

Ive never seen, coils with colour coded bands before, but if that’s all they are then I will try that solution.

Choke (inductor) colour coding

 

https://coil32.net/design/color-marking.html

 

Note that choke are that green colour with wide collars at each end, I've not yet come across a resistor that colour.

 

Andi

[BoD]

2 hours ago, TheKeg said:

Ive never seen, coils with colour coded bands before…

They do exist.

 

https://uk.farnell.com/bourns-jw-miller/78fr10m-rc/choke-100nh-500ma-20-400mhz/dp/1180366?st=rf choke

 

Being colourblind I can’t help with value but, as said,  if you replace with wire links, the colour doesn’t really matter.  Personally I prefer the nice striped two colour wire.
 

Just out of interest, how did they get like that?

Edited June 28, 2022 by BoD

[AndyID]

1 hour ago, BoD said:

Being colourblind I can’t help with value but,

 

 

From the left; brown, black, gold, silver.

 

If they are resistors that would make them one ohm. I think they probably are resistors because they do seem to have been dissipating a wee bit of power before they blew up 😀  Something like 10 watts might do it. If so they would have been passing around three amps.

 

(I suspect the wire in chokes would be more likely to fuse and go open-circuit.)

[Dagworth]

31 minutes ago, AndyID said:

 

From the left; brown, black, gold, silver.

 

If they are resistors that would make them one ohm. I think they probably are resistors because they do seem to have been dissipating a wee bit of power before they blew up 😀  Something like 10 watts might do it. If so they would have been passing around three amps.

 

(I suspect the wire in chokes would be more likely to fuse and go open-circuit.)

They are chokes, not resistors. End of

 

Andi

[KingEdwardII]

8 hours ago, Dagworth said:

They are chokes, not resistors

Just to be clear - inductors ("chokes", "coils") have a colour coding system similar to that for resistors, so that they might superficially be mistaken for resistors.

 

If you want to understand the inductor coding system, this page might be helpful:

 

https://www.electricaltechnology.org/2022/01/inductor-color-codes.html

 

Yours, Mike.

[Dungrange]

So following that website, Brown, Black, Gold, Silver (which is what it looks like to me) these must be one micro-henry with a tolerance of +/- 10%.

 

What exactly is the purpose of a choke?

[spamcan61]

RF interference supression, many DC locos these days have two series chokes and two shunt capacitors as the filter network.

Edited June 29, 2022 by spamcan61

[smokebox]

12 minutes ago, Dungrange said:

So following that website, Brown, Black, Gold, Silver (which is what it looks like to me) these must be one micro-henry with a tolerance of +/- 10%.

 

What exactly is the purpose of a choke?

 

They  oppose the flow of alternating current but allow direct current to flow freely*.  Capacitors have exactly the opposite effect on DC and AC.

 

*They will have a slight resistance, which opposes both AC and DC.

[AndyID]

1 hour ago, Dungrange said:

So following that website, Brown, Black, Gold, Silver (which is what it looks like to me) these must be one micro-henry with a tolerance of +/- 10%.

 

What exactly is the purpose of a choke?

 

As Spamcan says they are often used to suppress radio-frequency interference although they have lots of other applications. Digital signals change voltage very rapidly which produces lots of high frequencies. Chokes reduce the rate of change of voltage to reduce the higher frequencies.

 

One way to settle the choke/resistor question might be to measure the resistance between the internal black lump and the lead at the opposite end. If it's insulated it's most likely a choke and if it has resistance its more likely a resistor.

[Dagworth]

Why do you have to keep saying it might be a resistor? Being that colour it is a choke. 
 

Andi

[AndyID]

1 hour ago, Dagworth said:

Why do you have to keep saying it might be a resistor? Being that colour it is a choke. 
 

Andi

 

If you mean the body color I have resistors that are that color.

[MartinRS]

16 minutes ago, AndyID said:

 

If you mean the body color I have resistors that are that color.

It is not just the colour. Resistors have parallel sides. If you replace it with a wire, as one poster has sugested you might create interference on TV and radio broadcasts (which is an offence!). For examples see https://www.ebay.co.uk/itm/361973005363?hash=item544745bc33:g:-4cAAOSwQHpbBA9j&amdata=enc%3AAQAHAAAA4N5N3qw1A4d9XgcuyKpk5zJFM%2BN6mcP7B2XWCS%2BAt0zeqAdwp3kxfA9sEHgxM4c8Cnl5F39qtqpFwPqsp7e5GdydlXW4daQ5W7mxqcC1c7ijQHQmV4sVSid9%2BGdZj4krF8PQreoo4M0t6%2BOulgs1rvgzHWvN38ON5zeT%2FYRI8J77SIorf402oOce57nGuy7EZ1hcIMsIvKGPbF1TPbLmds%2F08O%2FplfLPoUqxXIVATcZzIpHHnH2yp4cspXmYFMJflBqhk7G5CcE%2BEqOhOlBwQGEsX7PwgzVhAm%2FbA1%2BTOblq|tkp%3ABFBMpPWTlbZg

[AndyID]

11 minutes ago, MartinRS said:

It is not just the colour. Resistors have parallel sides. If you replace it with a wire, as one poster has sugested you might create interference on TV and radio broadcasts (which is an offence!). For examples see https://www.ebay.co.uk/itm/361973005363?hash=item544745bc33:g:-4cAAOSwQHpbBA9j&amdata=enc%3AAQAHAAAA4N5N3qw1A4d9XgcuyKpk5zJFM%2BN6mcP7B2XWCS%2BAt0zeqAdwp3kxfA9sEHgxM4c8Cnl5F39qtqpFwPqsp7e5GdydlXW4daQ5W7mxqcC1c7ijQHQmV4sVSid9%2BGdZj4krF8PQreoo4M0t6%2BOulgs1rvgzHWvN38ON5zeT%2FYRI8J77SIorf402oOce57nGuy7EZ1hcIMsIvKGPbF1TPbLmds%2F08O%2FplfLPoUqxXIVATcZzIpHHnH2yp4cspXmYFMJflBqhk7G5CcE%2BEqOhOlBwQGEsX7PwgzVhAm%2FbA1%2BTOblq|tkp%3ABFBMpPWTlbZg

 

Yes, they do look very much like the destroyed example above. The gold and silver bands are the same and I don't remember ever seeing resistors with both.

 

Those ones are only rated for a quarter watt too.

[MartinRS]

17 minutes ago, AndyID said:

 

Yes, they do look very much like the destroyed example above. The gold and silver bands are the same and I don't remember ever seeing resistors with both.

 

Those ones are only rated for a quarter watt too.

That's because both gold and silver indicate the tolerance of a resistor with gold indicating the value plus or minus 5% and silver indicating 10%. A resistor can't be both. One way to remember the resistor colour code is by the mnemonic "Betty Brown runs over your garden but Violet Gray walks". It has a couple of advantages over other mnemonics: it won't cause offence; it incorporates some of the colour names.

[AndyID]

2 minutes ago, MartinRS said:

That's because both gold and silver indicate the tolerance of a resistor with gold indicating the value plus or minus 5% and silver indicating 10%. A resistor can't be both. One way to remember the resistor colour code is by the mnemonic "Betty Brown runs over your garden but Violet Gray walks". It has a couple of advantages over other mnemonics: it won't cause offence; it incorporates some of the colour names.

 

Good luck finding a 10% resistor these days. Until recently I actually had some that had been kicking around for about sixty years 😀

 

 

[MartinRS]

28 minutes ago, AndyID said:

 

Good luck finding a 10% resistor these days. Until recently I actually had some that had been kicking around for about sixty years 😀

 

 

My practical experience of electronics is a bit out of date (other than swapping cards out at work.) I played around with automatic control of model railways, using relays at first. Then I got into electronics which led me in the realm of home computers, as they were called then. I lost interest in electronics when I built my first computer way back in 1979, a UK101 !

[Michael Hodgson]

9 minutes ago, MartinRS said:

 I lost interest in electronics when I built my first computer way back in 1979, a UK101 !

I think mine is still buried in the loft somewhere, along with a couple of BBC micros, and of course a cassette recorder

[melmerby]

The body colour is irrelevant.

I've got modern close tolerance resistors in at least 3 different body colours: Blue, Green, grey.

e.g. 6 bands; grey body: white, brown, black, black, brown, red = 910 ohm, 1%, 50ppm/K.

 

The shape gives it away, it is bobbin with wire wrapped on it, i.e. a choke/inductor.

Edited June 29, 2022 by melmerby

[AndyID]

12 minutes ago, MartinRS said:

My practical experience of electronics is a bit out of date (other than swapping cards out at work.) I played around with automatic control of model railways, using relays at first. Then I got into electronics which led me in the realm of home computers, as they were called then. I lost interest in electronics when I built my first computer way back in 1979, a UK101 !

 

I built my first computer using DEC PDP16 modules. That was around 1972. Then I built a computer around an Intel 8080. Possibly the first 8080 to arrive in the UK. It didn't work properly! I found a bug before Intel knew about it. They circumvented it by adding a goofy external NAND gate in the data sheet 😀

[melmerby]

8 minutes ago, Michael Hodgson said:

I think mine is still buried in the loft somewhere, along with a couple of BBC micros, and of course a cassette recorder

My BBCs (Model B & Master) when to the tip.

I wish I had kept one of them.

[Crosland]

13 hours ago, MartinRS said:

Resistors have parallel sides.

 

Not always.

 

In fact, I would say resistors with end bulges are in the majority. Every single on on a number of PCBs on my desk in front of me have bulges at the ends.

 

The only definitive proof is to know more about the circuit where it came from.