Design rule ?

of)

It was something you may not have encountered recently, namely good-natured teasing.

Google "Rich the Philosphizer" if you don't remember.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

:

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I don't find it difficult to remember Rich the Philosopher - unprofitable, but not difficult. I can't say I enjoy being equated to him - I can see the teasing element, but the good-natured component rather escapes me.

-- Bill Sloman, Nijmegen

left of)

That explains a lot.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

"Spehro Pefhany" "Arfa Daily"

** A quick browse of the 5x20mm fuses on offer in my copy of the Farnell cat showed that the ceramic ones had a breaking capacity of ** 1500A ** . ** Bollocks.

5x20mm fuses are the standard across Europe, Asia and Australia for any equipment that plugs into a consumer AC outlet.

** Where the AC outlet uses a domestic type connector, there MUST be a breaker or fuse with rating matching the cable feeding that outlet ie, a 16 or 20 amp breaker. With a fault current of 150A or more, either of these will open in 1 or 2 mS.

Such breakers have the ability to interrupt 6kA or much - which equates to a dead short, right at the outlet.

Also, in the UK, there are *HRC* fuses fitted inside the 3 pin AC plugs, with ratings up to a max of 13A to protect cable and equipment.

... Phil

Hence the word "glass" up above there in my post. Ceramic ones are much, much better.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

"Spehro Pefhany" "Phil Allison"

** I mentioned the case of ceramic to counter the impression that there was an inherent problem with the 5mm x 20 mm SIZE of the fuse.

You have rudely snipped the rest of my post where I correct your other fallacies about fusing.

So I expect you are now suitably chastised ?

.... Phil

It could be a problem if the customer replaces the ceramic with a glass. What's common in the UK? In Canada the ceramic fuses are not as common.

I had no comment on those, as I don't have any reason to disagree, so snipped them. Do you want a pat on the back? Consider yourself patted. I don't think it was particularly rude.

"Suitably" is a very good word.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

"Spehro Pefhany"

** Never matters with supply fuses .in consumer equipment

** Ceramic HRC fuses inside the PLUGS !

** Yawnnnnn....

... Phil

Both glass and ceramic fuses inside the equipment, are common. As Phil rightly says, there is a fuse in the wall plug which is always ceramic. These are a slightly different size to a 5 x 20 mm fuse, but close. They are available in a number of different values from (commonly) 3 A up to 13 A. It is very common to find ordinary glass fuses in the mains feed on many items of consumer electronics which use linear supplies. However, the mains input fuse on switchers, is very often a ceramic HRC type

Arfa

Doesn't that require a fused cord outlet, if it doesn't use a fused plug?

It did when I was in the UK, and needed to know such things.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

MOVs are only suitable for suppression of voltage spikes, not continuous overvoltage. An MOV trip on a fast spike probably won't blow the fuse.

Which one blows on a continuous overvoltage depends on the MOV's joule rating, and the I-squared-t of the fuse.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Not always. Manufacturers differ.

Epcos versus Panasonic, IIRC.

The only sure way is read the *appropriate* data sheet.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Detroit est détruit?

-- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)

It actually becomes supplemental to an existing item which I cannot be more specific about because of confidentiality issues. That item may be connected via a fused spur, or a standard 13 A plug.

Arfa

for=20

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You got a rather larger than normal transient then. If you are really interested you can obtain the ANSI/IEEE C62.41 series (some hundreds of US$). It seems that the fuse and maybe the MOV were selected for a Catagory A environment (already protected and close to that protection) and got a Catagory B (partially protected or somewhat distant from the main protection) or a Catagory C (unprotected) class transient.

By fluke of chance, i have been into that for the last few days in my = POE.

?-)

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I saw it in thread somewhere It is a F200 200 mA very fast blow. Not a reasonable choice in front of a MOV.

?-)

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A 1/10 or 1/8 A slow blow or semi-slow blow is appropriate for this use (assuming nominal 120V main). A regular blow 1/10 A fuse would be fine without the MOV.

?-)

Grise

three

verbose

to

Bill, with all the time you have claimed to have, in a different post, haven't you just built your oscillator?

?-)

Noted. Thanks for your input.

Arfa