Fuse or fusible resistor?

Jun 27, 2010 20 Replies

Used in the battery (-) lead of a handheld scope. Schematics unpublished.



Physically similar to a 1/4 W resistor, color light green. Marked "IE7A" or "1E7A".



Google returns slim results, none promising.



What type is this?



Thanks, Dave



On 6/26/2010 9:56 PM Salmon Egg spake thus:

A grammar nanny, eh?

You must be a big hit at parties ...

Idiot ^^^^^ Not a complete sentence ^^^^^^^^^^^^^^^^^^^^^^^ Not a complete sentence

Etc.

John

I should have figured that not a goddamned soul actually tried to answer the question.

It sounds like a 'soft-fuze'. That resets itself after tripping.

There is also a similar device used in hair dryer circuitry.

"DaveC" <

** Sounds like a Pico Fuse:

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Come in fast and very fast ratings with amps rated from 1A to about 15A.

When they blow, you need a soldering iron to replace them.

There are various Asians clones too.

..... Phil

"DaveC"

** Sure that is not the other way around ?

Pico Fuse would use " 7A LE " as a the marking for a 7 amp fuse.

.... Phil

I take it , that its blown and I also take it that its not charred (fusible R don't char or even discolour AFAIK) Desolder it and scrape an axial line along its length . Then DVM resistance check from either end. If a fusible resistor then maximum R read is what its value was near enough. FR breaks are usually to one end, normal R usually in the middle. Although green is often axial inductor.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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No, I don't have one. I threw it out with the old battery. :-( Someone on-line volunteered to describe the one from his scope. I'll not ask him to do a post-mortem on a working fuse. ;-)

Thanks, Dave

Fuse. Ratings of these beasts in equipment is almost NEVER disclosed - like a company secret more precious than any other secret they have. Measure current draw and see what the maximum is during any operations, double that for a guide in choosing "first guess" replacement.

The axial leaded jobs I have seen in hair dryers are high current jobs with reed switches inside them. Not the soft break jobs.

The biggest soft device I recall was 3 Amps.

Could that be because no one knew what tghe question was?

Idiot

And that's why markings are so important. You can circumvent any need to measure.

Fester Bestertester wrote in news: snipped-for-privacy@news.eternal-september.org:

Oh man, has science really come to this? >:)

They are complete s

Just not ones that you

What I am writing, are incomplete sen

And don't

We don't like that on sci

Arf

and several other fuse manufacturers list E as .375A. If you read the data sheets, you should be able to determine what family you need.

unpublished.=20

Obviously, it's 10,000,000 amperes ;^)

Tim

--=20 Deep Friar: a very philosophical monk. Website:

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They won't catch fire but I have seen them char slightly. It's also common for them to crack or blow out a small chip of ceramic if something shorts and exposes them directly to the line voltage.

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