Author Topic: Identification of resistor type  (Read 1052 times)

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Offline TracelessTopic starter

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Identification of resistor type
« on: August 22, 2022, 07:43:18 pm »
Most handheld DMMs have a pair of green resistors close to the input jacks (see picture). Judging by the size those are 2 or 3W resistors, but what type are they? Carbon film, metal oxide film, sth else? I've been looking at some parts distributors for similar items but most have different colors (mostly white or brown). The only green ones I found don't have the color band code.

 

Offline TimFox

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Re: Identification of resistor type
« Reply #1 on: August 22, 2022, 08:19:40 pm »
My guess is metal-oxide (cermet) 2 W flame-proof resistors.
 

Offline Swainster

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Re: Identification of resistor type
« Reply #2 on: August 22, 2022, 08:59:53 pm »
The ones in the pic look like Bourns FW series fusible wirewound.
 

Offline Wallace Gasiewicz

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Re: Identification of resistor type
« Reply #3 on: August 22, 2022, 10:47:00 pm »
Fifth Band on Resistor

Black- Wire Wound
White Fusable

Otherwise it is tolerance

Perhaps the 5th band is white and discolored somewhat, at least may appear so in the picture, which is quite good.
 

Offline exmadscientist

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Re: Identification of resistor type
« Reply #4 on: August 23, 2022, 04:00:03 am »
It's possible they're ceramic composition types. I have a few of those lying around unused from an old project that are dead ringers for that body shape and color. The bands don't match though, so  :-//
 

Offline TracelessTopic starter

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Re: Identification of resistor type
« Reply #5 on: August 23, 2022, 05:40:18 am »
Thanks everyone for their feedback so far, since we were not 100% sure yet what the type is - with the majority leaning towards fusible and/or wirewound, eventually (Bournes FW series) which indeed looks similar I looked up one of Dave's teardowns (Fluke vs. Brymen., link below, resistors are visible around timestamp 16:45 and later) for additional reference. Similar resistors can be seen on both meters during the teardown albeit those have only a 4-band code. They seem to serve the same purpose as the resistors on the picture above. In the video Dave also states that these four-band ones are "fusible resistors". So I think probably Swainster identified them correctly and will assume they are indeed Bournes FW wirewound types.

Does anyone know if there is a significat difference between those green types and those white ones?



« Last Edit: August 23, 2022, 05:56:37 am by Traceless »
 

Offline abdulbadii

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Re: Identification of resistor type
« Reply #6 on: August 23, 2022, 10:25:13 am »
roughly




fusible if silver/white is the last band
« Last Edit: August 26, 2022, 03:38:58 am by abdulbadii »
 


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