|
Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
|
Thread Tools |
10th Jun 2018, 5:58 pm | #1 |
Octode
Join Date: Jan 2012
Location: Wimbledon, London, UK.
Posts: 1,465
|
Another strange component
Hi,
Some time ago I was given an enormous bag of assorted resistors. I recently managed to sort them out and now have a lot of useful resistors. There were two that puzzle me, though. They look like resistors, as can be seen from the attached photo, but the measured values and colour-code don't seem to make much sense to me. The colour-code is brown/green/gold/black or vice versa, but I can't see how a colour-code can sensible start with a black band. My bridge measures them to be 1R5, but my Chinese component-tester gives 0.4R. I have tentatively identified them as 1R5, 0.05%, but remain unconvinced. Neither my bridge nor my component-tester indicate any other properties such as inductance. Any ideas? |
10th Jun 2018, 6:14 pm | #2 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
|
Re: Another strange component
There are plenty of low-value inductors that look like that.
See http://www.learnabout-electronics.or...nductors04.php |
10th Jun 2018, 6:34 pm | #3 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Another strange component
If it's an inductor then 0.5uH would be my guess:
http://coil32.net/online-calculators...alculator.html EDIT: Whoops, I missed the colours you described, so yes, 1.5uH Lawrence. Last edited by ms660; 10th Jun 2018 at 6:43 pm. |
10th Jun 2018, 6:35 pm | #4 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,578
|
Re: Another strange component
More likely to be an inductor, 1.5uH.
__________________
There are lots of brilliant keyboard players and then there is Rick Wakeman..... |
10th Jun 2018, 6:39 pm | #5 |
Nonode
Join Date: Aug 2007
Location: Walsall Wood, Aldridge, Walsall, UK.
Posts: 2,873
|
Re: Another strange component
Hi!
It's a 1.5uH axial inductor about 1A d.c. current rating! Colour-coded inductors code in micro-henries, e.g., brown-black-black = 10uH, brown-black-brown = 100uH, brown-black-red = 1mH and so on! The clue that it's an inductor rather than a resistor is the wasp-waisted shape of the body - a resistor body is much more parallel-sided! Chris Williams
__________________
It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed! |
10th Jun 2018, 6:52 pm | #6 |
Rest in Peace
Join Date: Feb 2004
Location: Hexham, Northumberland, UK.
Posts: 2,234
|
Re: Another strange component
I would agree, looks like an inductor. I have seen these on bandoliers mixed with resistors for automatic assembly so maybe that's why you have a mix in your pack.
|
10th Jun 2018, 8:10 pm | #7 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
|
Re: Another strange component
I read that code as 1, 5, divide by 10, give or take 1%, and it looks more like an inductor than a resistor, so a 1.5µH inductor would be my guess. A 1.5Ω resistor would not usually be so much fatter at the ends than in the middle.
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments. |
11th Jun 2018, 2:07 pm | #8 |
Heptode
Join Date: Dec 2014
Location: Lincoln, Lincolnshire, UK.
Posts: 583
|
Re: Another strange component
To give the resistance perspective, the tables of similar inductors I use give the resistance of a 1.5UH inductor as around 0.2 to 0.3 Ohm.
|
11th Jun 2018, 5:24 pm | #9 |
Octode
Join Date: Jan 2012
Location: Wimbledon, London, UK.
Posts: 1,465
|
Re: Another strange component
Thanks, folks, for solving this. I have checked it on my Tek Type 130 and it measures at 1.5uH, as suggested. The oddity, though, is that my Marconi TF 2700 bridge has it at 5.6uH. The bridge is fine for resistance, so what could be the problem, do you think?
Colin. |
11th Jun 2018, 5:37 pm | #10 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,554
|
Re: Another strange component
I have got a Marconi TF1313A and it has a Q control that makes a lot of difference to the read value. It is very accurate once you get used to using it and would also get the correct value for that choke.
|
11th Jun 2018, 10:11 pm | #11 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,579
|
Re: Another strange component
Hi
I tend to agree it's a 1.5uH inductor. Normally 1.5uH would be Brown Green Gold usually with a Gold tolerance band also so the black band is a bit of a puzzler. Regards Symon |
12th Jun 2018, 8:04 am | #12 | |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,991
|
Re: Another strange component
Quote:
Craig |
|
12th Jun 2018, 11:00 am | #13 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,554
|
Re: Another strange component
It takes a little bit of learning to get confident with the TF1313A but once you are there your are sure.
It is indeed worth the bench space as anything modern would cost a fortune to get the accuracy of the TF1313A. |