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'[OT]: Radio Shack'
2003\03\13@172449 by Alex Kilpatrick

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I blew the 100 mA fuse in my meter (fourth time now), so I thought I
would see if Radio Shack had any.  Unfortunately, the smallest they had
was .5 A.  I talked to one of the sales guys there, and he said "it is
no problem if you just use a bigger fuse."  Ack!  I explained the basic
concept of fuses to him, but I am not sure how much it sunk in.

I don't expect much from Radio Shack, but this is almost criminal.  I
wonder how much damage he is responsible for?


Alex

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2003\03\13@173137 by Sid Weaver

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In a message dated 03/13/2003 17:25:37 Eastern Standard Time,
spam_OUTAlexKTakeThisOuTspamHCITRAINING.COM writes:


> I don't expect much from Radio Shack, but this is almost criminal.  I
> wonder how much damage he is responsible for?
>

People in Radio Shack are like any other group - mechanics, cooks, house
painters.  Some are downright stupid, some are good, and some are
outstanding.  It's all potluck.  You just have to be alert.

Sid Weaver
W4EKQ
Port Richey, FL

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2003\03\13@173944 by Peter Barick

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>>> .....AlexKKILLspamspam@spam@HCITRAINING.COM 03/13/03 04:23PM >>>
"
I blew the 100 mA fuse in my meter ...
see if Radio Shack had any. ...
he said "it is no problem if you just use a bigger fuse."
Ack! ...
I wonder how much damage he is responsible for?
"
--------------------------------------

Come on, Alex, he's a salesman first; your personal electronic
"know-it-all" ninth - well maybe eighth.

Peter, who's given up on training sales staffs but grins just the same

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2003\03\13@174359 by Brendan Moran

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>I blew the 100 mA fuse in my meter (fourth time now), so I thought I
>would see if Radio Shack had any.  Unfortunately, the smallest they had
>was .5 A.  I talked to one of the sales guys there, and he said "it is
>no problem if you just use a bigger fuse."  Ack!  I explained the basic
>concept of fuses to him, but I am not sure how much it sunk in.
>
>I don't expect much from Radio Shack, but this is almost criminal.  I
>wonder how much damage he is responsible for?

While I was working in quality control for a company (pcb assembly) that
shall remain nameless,  I once found a set of boards that had had their 5A
SMD fuses replaced with 6.5A SMD fuses during the assembly process.  I was
doing second inspection (someone else had already inspected the boards) so
I realized that there could be many more of these that had gone through
another QC, so I took it to my supervisor, and he said "Hmm, lets see,
6.5A, so that won't blow before it's supposed to, right?"  I looked at him
in horror for a few seconds, and I think that twigged his higher logic
functions, since we then went and hunted down all the other mis-fused
boards and got them fixed.

Like your Radio Shack guy, I wonder how much damage my QC supervisor was
responsible for.  I don't think he had even a cursory understanding of
electronics, and was working in an electronics assembly house...  *sigh*

--Brendan

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2003\03\13@174758 by Alex Kilpatrick

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> >
> >I don't expect much from Radio Shack, but this is almost
> criminal.  I
> >wonder how much damage he is responsible for?
>
> While I was working in quality control for a company (pcb
> assembly) that shall remain nameless,  I once found a set of
> boards that had had their 5A SMD fuses replaced with 6.5A SMD
> fuses during the assembly process.  I was doing second
> inspection (someone else had already inspected the boards) so
> I realized that there could be many more of these that had
> gone through another QC, so I took it to my supervisor, and
> he said "Hmm, lets see, 6.5A, so that won't blow before it's
> supposed to, right?"  I looked at him in horror for a few
Well, he was right.  It won't blow before it is supposed to.  It will
blow after.  
:-)

What in the heck were you working on that had a 5A fuse?  Yeesh.

Alex

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2003\03\13@175410 by Brendan Moran

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>Well, he was right.  It won't blow before it is supposed to.  It will
>blow after.
>
>:-)
>
>What in the heck were you working on that had a 5A fuse?  Yeesh.
>
>Alex

Well, it was some form of battery charger I think.  Some kind of energy
transfer related board, in any case.  Being a QC at the time, I didn't get
much info on what it was, only on what was supposed to be on it.

;)

--Brendan

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2003\03\13@180210 by Neil Cherry

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Alex Kilpatrick wrote:
> I blew the 100 mA fuse in my meter (fourth time now), so I thought I
> would see if Radio Shack had any.  Unfortunately, the smallest they had
> was .5 A.  I talked to one of the sales guys there, and he said "it is
> no problem if you just use a bigger fuse."  Ack!  I explained the basic
> concept of fuses to him, but I am not sure how much it sunk in.
>
> I don't expect much from Radio Shack, but this is almost criminal.  I
> wonder how much damage he is responsible for?

<HUMOR>

Easy enough to teach them the importance of proper fuse sizing. hand the
sales associate 2 wires (make them 10 guage) one in each hand. On one
wire have a fuse holder and ask the sales associate if he wants a 100 mA
fuse or a .5A fuse. :-) You're idea of the appropriate voltage can be
used, personally I prefer a demonstration with DC and something like
48V but 220 AC could be fun too.

</HUMOR>

DO NOT try this, the text is just meant as a joke!


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2003\03\13@180948 by William Chops Westfield

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I dunno.  In modern electronics, fuses generally protect against relatively
catastrophic failures, and it seems pretty likely that increasing the value
of a fuse by an amp or two isn't really that likely to be a terrible thing.
(ie fuses are too slow to protect electronics; they primarilly protect
against fires and such.  Can you actually imaging a failure mode where
your ~3A circuit draws more than 5A but less than 6.5A, and explain why
that's particularly dangerous?)

The 100mA fuse in a meter presuambly protectst the meter movement itself,
right?  Or maybe it stops the shunt resistor from burning up.  So maybe
it's more critical...

BillW

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2003\03\13@182353 by Alex Kilpatrick

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>
>
> I dunno.  In modern electronics, fuses generally protect
> against relatively catastrophic failures, and it seems pretty
> likely that increasing the value of a fuse by an amp or two
> isn't really that likely to be a terrible thing. (ie fuses
> are too slow to protect electronics; they primarilly protect
> against fires and such.  Can you actually imaging a failure
> mode where your ~3A circuit draws more than 5A but less than
> 6.5A, and explain why that's particularly dangerous?)
>
> The 100mA fuse in a meter presuambly protectst the meter
> movement itself, right?  Or maybe it stops the shunt resistor
> from burning up.  So maybe it's more critical...
>
It is a digital meter.  The 100 mA fuse is probably not there to prevent
a fire. :-)

I assume it protects sensitive electronics that measure small current.
The meter will measure down to uA.


Alex

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2003\03\13@183401 by jim barchuk

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Hi BillW!

On Thu, 13 Mar 2003, William Chops Westfield wrote:

> I dunno.  In modern electronics, fuses generally protect against
> relatively catastrophic failures, and it seems pretty likely that
> increasing the value of a fuse by an amp or two isn't really that likely
> to be a terrible thing. (ie fuses are too slow to protect electronics;
> they primarilly protect against fires and such.  Can you actually
> imaging a failure mode where your ~3A circuit draws more than 5A but
> less than 6.5A, and explain why that's particularly dangerous?)

That's not the point. The manufacturer is Responsible for the quality and
function of the product. With a capital 'R'. QC is responsible for
assuring the quality. The poster did his job 100& right. If something
blows up, or catches fire, or kills someone, the manufacturer, and the QC
if he -knew- about the mistake but -didn't- do anything about it, is
responsible. Ethically and legally. Possibly criminally. How heavy a
weight would you want hanging over -your- head when you put your little
stamp on that slip of paper that says 'OK - WCW'? Would you use an
electric lawn mower on a damp day if you knew the fuse had been replaced
with a higher rating? LOL! Think about it on a personal level and it
becomes a little more important.

Have a :) day!

jb

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2003\03\13@184856 by Brendan Moran

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>That's not the point. The manufacturer is Responsible for the quality and
>function of the product. With a capital 'R'. QC is responsible for
>assuring the quality.

Couldn't have said it better myself, thx.

--Brendan

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2003\03\13@192454 by Ned Konz

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On Thursday 13 March 2003 02:23 pm, Alex Kilpatrick wrote:
> I don't expect much from Radio Shack, but this is almost criminal.
>  I wonder how much damage he is responsible for?

Isn't Radio Shack's motto something like:

Radio Shack: you've got questions, we've got blank looks.

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http://bike-nomad.com
GPG key ID: BEEA7EFE

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2003\03\13@194811 by John Nall

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>People in Radio Shack are like any other group - mechanics, cooks, house
>painters.  Some are downright stupid, some are good, and some are
>outstanding.  It's all potluck.  You just have to be alert.

I've been dealing with Radio Shack for many years.  It is about the only
game in town, here, and if you only want a couple of 1/4 watt resistors you
do not particularly want to order from DigiKey.  And also, sometimes you
are in a hurry.  Some of the people I've met are very knowledgeable (most
of the knowledgeable ones are hams, for whatever that may be worth) and
some are not.   One of the managers is a friend of mine, and he says that
they would absolutely love to hire talented, knowledgeable experts if they
could find them for what they can pay.  But they kind of have to take what
they can get.

John

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2003\03\13@195912 by Sid Weaver

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In a message dated 03/13/2003 19:48:38 Eastern Standard Time,
EraseMEjnall01spam_OUTspamTakeThisOuTALLTEL.NET writes:


{Quote hidden}

I"m with you, John.  I live in a small town and they have saved my butt many
a time.  Need a cap - 15 minutes instead of 4 days, no minimun, no freight.
They don't have everything, but almost.

Sid

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2003\03\13@200328 by Matt Pobursky

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On Thu, 13 Mar 2003 14:43:27 -0800, Brendan Moran wrote:
> While I was working in quality control for a company (pcb assembly)
> that shall remain nameless,  I once found a set of boards that had
> had their 5A SMD fuses replaced with 6.5A SMD fuses during the
> assembly process.  I was doing second inspection (someone else had
> already inspected the boards) so I realized that there could be many
> more of these that had gone through another QC, so I took it to my
> supervisor, and he said "Hmm, lets see, 6.5A, so that won't blow
> before it's supposed to, right?"  I looked at him in horror for a few
> seconds, and I think that twigged his higher logic functions, since
> we then went and hunted down all the other mis-fused boards and got
> them fixed.


> Like your Radio Shack guy, I wonder how much damage my QC supervisor
> was responsible for.  I don't think he had even a cursory
> understanding of electronics, and was working in an electronics
> assembly house...  *sigh*

Personally, I don't really want a production person to know much, if anything about electronics. That will just encourage them to think about things they don't need to, like whether it's OK to substitute a part or not. That's the engineer's job. I want them to know how to follow documentation, build things per the documentation, question the
documentation if it does look suspect and reject anything not built to
spec. That doesn't require any electronics knowledge at all, but it
does require common sense and good judgment.

Matt Pobursky
Maximum Performance Systems

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2003\03\13@200927 by Matt Pobursky

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On Thu, 13 Mar 2003 18:34:29 -0500, jim barchuk wrote:
> That's not the point. The manufacturer is Responsible for the quality
> and function of the product. With a capital 'R'. QC is responsible
> for assuring the quality. The poster did his job 100& right. If
> something blows up, or catches fire, or kills someone, the
> manufacturer, and the QC if he -knew- about the mistake but -didn't-
> do anything about it, is responsible. Ethically and legally. Possibly
> criminally. How heavy a weight would you want hanging over -your-
> head when you put your little stamp on that slip of paper that says
> 'OK - WCW'? Would you use an electric lawn mower on a damp day if you
> knew the fuse had been replaced with a higher rating? LOL! Think
> about it on a personal level and it becomes a little more important.

My best friend is the director of manufacturing for a medical company
that designs and manufactures infusion pumps (they are also a client of
mine). He has a great saying he teaches to *ALL* his employees, from
the technician, assembly line personnel, even the paper pushers...

"Would you hook this device up to your spouse or child?"
Kinda gets the point across on a personal basis.

Matt Pobursky
Maximum Performance Systems

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2003\03\13@201542 by Benjamin Bromilow

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Radio Shack in the UK filled a hole in the market. Available all over the
place and accessable, they were great when you let the magic smoke out of
something (I remember a memorable day when I literally blew the top off a
555)... Shame they've now all been turned into Carphone Whorehouses :)
Where I live in Nottingham, Maplins are right next to PC World. It appears
Maplins is slowly turning into it's neighbour. If you want a new mouse of
some CD-Rs, no problems. If you want anything to do with electronics
though... I went today and they only had 50% of what I wanted. They've also
dropped off the multi-way connectors I was rather fond of.....
I suppose it's the price I pay for using Crownhill or other mail order
places because they're cheaper....

YMMV,

Ben

{Original Message removed}

2003\03\13@203427 by Chris Loiacono

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I have to disagree strongly here.
Experience has taught me that there is great value in being surrounded by
the most skilled and knowlegeable people that can be found. Wanting to keep
'em *stoopid*  (thanks for the great word Dwayne!) is a trait of many
managers who either feel challenged by intelligent people, or who only know
how to motivate people of lesser intelligence. (I guess there is also the
military - where "need to know' and stupidity are inexplicably combined.)
Managers with up to date management skills know how to prevent each one from
overstepping their bounds in potentially harmful ways while helping them
expand their horizons and enhancing the value of the organization.

The Gallup organization recently released the results of a 25 year survey
that included profiling of > 2 million people. I was originally trained and
worked as an Industrial Engineer  - during those years I learned to question
the many theories that were developed on this subject many were based on the
author's desires to succed or on emotional or shock appeal - but Gallup has
compiled their results into a huge unbiased set of observation based facts.
Overwhelmingly, the record shows the import of developing employees skills
as one of the most common traits of successful managers....

I want production people who understand more than they 'need to'. Many, many
times I have seen the poor slob who presses pins into boards or loads
pallets into solder machines all day long discover the real reason for some
inexplicable intermittent failure problem while a team of EE's ponders over
the same. Likewise, many production people have become either initiated
patent apps or become patent holders because they observed something with
more understanding than they were 'supposed to' have. What a shame it would
be to not have this kind of exchange in any organization....

C
> Personally, I don't really want a production person to know much, if
> anything about electronics. That will just encourage them to think
> about things they don't need to, like whether it's OK to substitute a
> part or not. That's the engineer's job. I want them to know how to
> follow documentation, build things per the documentation, question the
> documentation if it does look suspect and reject anything not built to
> spec. That doesn't require any electronics knowledge at all, but it
> does require common sense and good judgment.
>

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2003\03\13@210339 by Sean H. Breheny

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I agree. Also, understanding why things have to be done a certain way
removes some of the temptation to cut corners. I've met production workers
who think that the engineering types just like to heap meaningless
requirements on them. I also found that someone who had a clue as to how
the devices worked almost never had this attitude.

There are also sometimes manufacturing processes (probably not PCB
assembly) that require considerable skill. Someone who understands why it
has to be done a certain way is more likely to learn the skill well and
learn it faster. I worked (only for a summer) at a place that did high
power laser diode packaging for fiber optic Erbium doped fiber amplifier
laser "pumps". One step in the assembly process involved lining up a single
mode fiber with a tiny laser diode die to get maximum power transfer and
then applying epoxy to several pieces to hold it all in place. There was a
very strong correlation between basic understanding and quality of work.
Some people never learned how to do it well because they didn't understand
what was critical and what wasn't.

Sean

At 08:35 PM 3/13/2003 -0500, you wrote:
{Quote hidden}

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2003\03\13@212032 by Dave Tweed

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Alex Kilpatrick <AlexKspamspam_OUTHCITRAINING.COM> wrote:
> It is a digital meter.  The 100 mA fuse is probably not there to prevent
> a fire. :-)

Actually, it is. It's for when you forget that the meter is in current mode
and you put it across a voltage source. The fuse prevents the test leads
from melting in your hands. A 500 mA fuse works just as well as a 100 mA
fuse for this purpose.

> I assume it protects sensitive electronics that measure small current.
> The meter will measure down to uA.

It's actually fairly easy to protect the electronics from overvoltage
faults. You need to do this anyway, as the fuse cannot possibly blow
quickly enough to protect them.

I'll grant you that many RS employees are fairly dim bulbs, but in this
particular case, he did *not* give you bad advice.

As far as being "horrified" about a change from a 5A to a 6.5A fuse,
there's the QC point of view and the engineering point of view. From the
QC point of view, it is manufacturing's responsibility to produce the
product that engineering specified. *Any* deviation is a cause for concern.

However, from an engineering point of view, fuses are very sloppy
devices. If you've ever looked at the percent overload vs. opening time
curve for a typical fuse, you'd understand this. They don't even specify a
minimum opening time, just a maximum for certain levels of overload. They
sometimes even promise that the fuse *won't* open for certain small
overloads (like 125%), so you know what kind of design margin you have.
The actual difference between a 5A fuse and a 6.5A fuse is way down in the
noise.

-- Dave Tweed

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2003\03\13@212653 by Alex Kilpatrick

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> -----Original Message-----
> From: Dave Tweed [@spam@picKILLspamspamDTWEED.COM]
> Sent: Thursday, March 13, 2003 8:20 PM
> To: KILLspamPICLISTKILLspamspamMITVMA.MIT.EDU
> Subject: Re: [OT]: Radio Shack
>
>
> Alex Kilpatrick <RemoveMEAlexKTakeThisOuTspamHCITRAINING.COM> wrote:
> > It is a digital meter.  The 100 mA fuse is probably not there to
> > prevent a fire. :-)
>
> Actually, it is. It's for when you forget that the meter is
> in current mode and you put it across a voltage source. The
> fuse prevents the test leads from melting in your hands. A
> 500 mA fuse works just as well as a 100 mA fuse for this purpose.
>
Are you sure?  My meter (Fluke) has two possible inputs for measuring
current.  One goes up to 10A (I think) and one is fused at 100 mA.  If
it isn't fast enough to save the electronics, then what is it for?  Why
not just have one input at 10A?

Radio Shack does have 500 mA fuses, so I would gladly use one if it is
going to be the same.

Alex

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2003\03\13@212905 by Benjamin Bromilow

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Just to add to the confusion I bought an electrical appliance the other day.
In the instruction manual it said "the appliance is supplied as standard
with a 5 Amp fuse. If this blows it should be replaced it with a 13A fuse".
I don't understand quite why even now. Perhaps they'd run out of 13A
fuses... This was in the mass produced printed instructions BTW!!!! If
anyone is interested I can pull out the maker and model....
I can't believe it was just the old adage "if the fuse blows use a bigger
one". I've seen enough domestic fuse boxes with 1/4" nails for fuses :(
I'm not as green as I'm cabbage looking, I just can't believe someone
responsible for a electronics firm would actually write this without good
reason (e.g. use of 110v rather than 240v on a given load)

Ben

{Original Message removed}

2003\03\13@213111 by William Chops Westfield

face picon face
   The manufacturer is Responsible for the quality and function of the
   product. With a capital 'R'. QC is responsible for assuring the
   quality. The poster did his job 100& right.

Oh, I agree with that.  I just don't think that the acceptance of the
"wrong" fuse by his boss(es) was so horrifying...


   Would you use an electric lawn mower on a damp day if you knew the
   fuse had been replaced with a higher rating? LOL!

Well, yes.  Cause *I* know that there ain't a fuse made that's going
to protect ME from electrocution.  20mA, remember...

BillW

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2003\03\13@213736 by William Chops Westfield

face picon face
> Actually, it is. It's for when you forget that the meter is
> in current mode and you put it across a voltage source. The
> fuse prevents the test leads from melting in your hands.

Well, a typical digital meter will run the current you're trying to measure
through a low-value shunt resistor, and then put the voltage drop through a
nice sensitive A-D converter.  At low current ranges, this "shunt resistor"
probably has a high precision, low wattage, and relatively high ohm value,
and I suspect that these resistors are what you are protecting with a fuse.
For the high current range, you probably have a high-power resistor of
rather lower precision and ohms, with accuracu suitable for measuring larger
currents...

Melting the leads can happen after the resistors "fail shorted", but I don't
think it is the primary concern...

BillW

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2003\03\13@214805 by Dave Tweed

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Alex Kilpatrick <spamBeGoneAlexKspamBeGonespamHCITRAINING.COM> wrote:
> Dave Tweed <TakeThisOuTpicEraseMEspamspam_OUTdtweed.com> wrote:
> > Alex Kilpatrick <RemoveMEAlexKspamTakeThisOuTHCITRAINING.COM> wrote:
> > > It is a digital meter.  The 100 mA fuse is probably not there to
> > > prevent a fire. :-)
> >
> > Actually, it is. It's for when you forget that the meter is
> > in current mode and you put it across a voltage source. The
> > fuse prevents the test leads from melting in your hands. A
> > 500 mA fuse works just as well as a 100 mA fuse for this purpose.
>
> Are you sure?  My meter (Fluke) has two possible inputs for measuring
> current.  One goes up to 10A (I think) and one is fused at 100 mA.  If
> it isn't fast enough to save the electronics, then what is it for?  Why
> not just have one input at 10A?

Quite sure. The 10A range uses a special shunt and very low-resistance
traces on the PCB to get good accuracy. At least, that's how it is on my
Heathkit DMM. The fact that there's a separate input means that they didn't
even want to run the current through the range switches.

The 100 mA fuse is also protecting the shunt(s) and the narrower PCB traces
used for the lower ranges, but I'd be very surprised (I was going to say
"shocked" but thought better of it :-) if they'd be damaged at 500 mA. At
least a 500 mA fuse will provide enough protection to let you keep going
until you can order some 100 mA fuses. Just be extra careful to double
check your meter settings before each measurement.

-- Dave Tweed

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2003\03\13@222340 by Vern Jones

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But never wet or dry, use the mower without a GFI breaker unless its a
battery operated one...
Vern

William Chops Westfield wrote:
{Quote hidden}

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2003\03\13@222603 by Brendan Moran

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>As far as being "horrified" about a change from a 5A to a 6.5A fuse,
>there's the QC point of view and the engineering point of view. From the
>QC point of view, it is manufacturing's responsibility to produce the
>product that engineering specified. *Any* deviation is a cause for conce

I know perfectly well about fuses, and the standard 15% overdesign that is
done on fuses.  But, frankly, here is a guy with a bachelors in process
management standing there trying to justify a problem in the board that all
the other QCs missed.  It's not so much that it had to be that particular
fuse, but more that we didn't know exactly why they had chosen a 5A fuse.

If you're a manufacturer and you don't know why a designer chose to use one
size of fuse, you have no right to change the fuse size.

--Brendan

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2003\03\13@222608 by Brendan Moran

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At 01:14 AM 14/03/2003 +0000, you wrote:
>Radio Shack in the UK filled a hole in the market. Available all over the
>place and accessable, they were great when you let the magic smoke out of
>something (I remember a memorable day when I literally blew the top off a
>555)... Shame they've now all been turned into Carphone Whorehouses :)
>Where I live in Nottingham, Maplins are right next to PC World. It appears
>Maplins is slowly turning into it's neighbour. If you want a new mouse of
>some CD-Rs, no problems. If you want anything to do with electronics
>though... I went today and they only had 50% of what I wanted. They've also
>dropped off the multi-way connectors I was rather fond of.....
>I suppose it's the price I pay for using Crownhill or other mail order
>places because they're cheaper....

I'm afraid that the only hole that Radio Shack is filling where I live is
the "Where do I buy a 555 for $5.55?" hole.  Ok, so I'm exaggerating it's
only $3.29 for a $0.40 chip, but still.

--Brendan

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2003\03\13@222613 by Brendan Moran

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>     Would you use an electric lawn mower on a damp day if you knew the
>     fuse had been replaced with a higher rating? LOL!
>
>Well, yes.  Cause *I* know that there ain't a fuse made that's going
>to protect ME from electrocution.  20mA, remember...

So, then would you use it without the GFCI?

--Brendan

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2003\03\13@224215 by Matt Pobursky

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I didn't say I wanted 'em stupid. In fact far from it.

I actually agree 100% with you and probably didn't state my opinion
very clearly. I think what I value most is common sense and a wide
range of knowledge. I know I've learned a lot by listening to
assemblers, QC inspectors, technicians and even (gasp) purchasing
agents.

On Thu, 13 Mar 2003 20:35:46 -0500, Chris Loiacono wrote:
{Quote hidden}

Yes, exactly. That sad fact is that most companies I've either worked
for or with this hasn't been the case.

{Quote hidden}

Also very true. I know I actually spend a lot of time working with
production people helping them understand exactly how things should
work. I also work exclusively with contract manufacturers (many not of
my choosing), so that may color my view of things too.

Matt Pobursky Maximum Performance Systems

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2003\03\13@224746 by Jake Anderson

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>and even (gasp) purchasing agents
NFW!

----- Original Message -----
From: "Matt Pobursky" <piclistEraseMEspam.....MPS-DESIGN.COM>
To: <EraseMEPICLISTspamMITVMA.MIT.EDU>
Sent: Friday, March 14, 2003 2:42 PM
Subject: Re: [OT]: Radio Shack


{Quote hidden}

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2003\03\13@225009 by Herbert Graf

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> > I don't expect much from Radio Shack, but this is almost criminal.  I
> > wonder how much damage he is responsible for?
> >
>
> People in Radio Shack are like any other group - mechanics, cooks, house
> painters.  Some are downright stupid, some are good, and some are
> outstanding.  It's all potluck.  You just have to be alert.

       That used to be true. These days finding a good one is becoming rarer and
rarer. All the radioshacks in my area have lost the "good ones", to be
replaced with useless ones. TTYL

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2003\03\14@005827 by Bob Blick

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> I don't expect much from Radio Shack, but this is almost criminal.  I
> wonder how much damage he is responsible for?

What do you expect, their motto is:

"You've got questions, we've got blank stares"

-Bob

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2003\03\14@024850 by hael Rigby-Jones

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> -----Original Message-----
> From: jim barchuk [SMTP:RemoveMEjbEraseMEspamEraseMEJBARCHUK.COM]
> Sent: Thursday, March 13, 2003 11:34 PM
> To:   RemoveMEPICLISTspam_OUTspamKILLspamMITVMA.MIT.EDU
> Subject:      Re: [OT]: Radio Shack
>
> Would you use an
> electric lawn mower on a damp day if you knew the fuse had been replaced
> with a higher rating? LOL! Think about it on a personal level and it
> becomes a little more important.
>
Probably, as long as it was still a 'reasonable' fuse rating (i.e. not a cut
down 6" nail).  In this type of application the fuse in the power connector
is mainly there to protect the cable.  Anyone with more than 1/2 a brain
would be using an RCD with any power tool anyway.

Regards

Mike



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2003\03\14@063303 by William Chops Westfield

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Heh.  Reminds me of the programming Koans attributed to folk at MIT:

   A novice was trying to fix a broken Lisp machine by turning the power
   off and on.

   Knight, seeing what the student was doing, spoke sternly: "You cannot
   fix a machine by just power-cycling it with no understanding of what is
   going wrong."

      Knight turned the machine off and on.

      The machine worked.

BillW

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2003\03\14@091739 by Paul Hutchinson

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There is a reason to make sure you don't substitute a 500mA fuse for the
100Ma one, protecting the ohms function. Connecting the leads to a power
source while in ohms mode with too large a fuse can turn your Volt-Ohm-Amp
meter into a Volt-Amp meter, I suspect it fries the ohms functions' current
source.

Paul

> {Original Message removed}

2003\03\14@094500 by Lawrence Lile

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Bill, you have a point.  I have done some detailed analysis of fuses, and
if you count the time-current curves, tolerances, and the fact that a fuse
is a thermal device, is ambient temperature sensitive, and a host of other
factors, "tain't much difference one fuse from another".

That said, I would NEVER advocate substituting the wrong value of fuse.
Somebody who desinged that product decided that was the best value and not
some other, and that person knew more about that product than I do.

I would also not advocate gettting any technical info from a radio shack
guy.  Time was, Radio shack was a magnet for geeks.  No longer, they sell
more radio controlled toys than resistors.  They say "Can I help you", and
I stare at them, and just walk back to the nuts and bolts section.


-- Lawrence Lile





William Chops Westfield <EraseMEbillwspamspamspamBeGoneCISCO.COM>
Sent by: pic microcontroller discussion list <RemoveMEPICLISTKILLspamspamMITVMA.MIT.EDU>
03/13/2003 05:08 PM
Please respond to pic microcontroller discussion list


       To:     PICLISTSTOPspamspamspam_OUTMITVMA.MIT.EDU
       cc:
       Subject:        Re: [OT]: Radio Shack


I dunno.  In modern electronics, fuses generally protect against
relatively
catastrophic failures, and it seems pretty likely that increasing the
value
of a fuse by an amp or two isn't really that likely to be a terrible
thing.
(ie fuses are too slow to protect electronics; they primarilly protect
against fires and such.  Can you actually imaging a failure mode where
your ~3A circuit draws more than 5A but less than 6.5A, and explain why
that's particularly dangerous?)

The 100mA fuse in a meter presuambly protectst the meter movement itself,
right?  Or maybe it stops the shunt resistor from burning up.  So maybe
it's more critical...

BillW

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2003\03\14@095742 by D. Jay Newman
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> guy.  Time was, Radio shack was a magnet for geeks.  No longer, they sell
> more radio controlled toys than resistors.  They say "Can I help you", and
> I stare at them, and just walk back to the nuts and bolts section.

They also used to have a fairly decent stock of parts (though very pricey).

Now they have the basics and they can't get anything else. Around here at
least. YMMV.
--
D. Jay Newman          ! Pudge controls the weather.
spamBeGonejaySTOPspamspamEraseMEsprucegrove.com    !
http://enerd.ws/~jay/  ! It's OK. My dog found the chainsaw.

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2003\03\14@202816 by Bill & Pookie

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I have a old motor/generator set that came with a
die to punch out it's fuses from a tin can.  Don't
need no Radio Shack for that.

Pookie

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2003\03\14@210833 by Jinx

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> I have a old motor/generator set that came with a
> die to punch out it's fuses from a tin can.  Don't
> need no Radio Shack for that.
>
> Pookie

Haha, like guitarists that stuff the fuseholder with silver
paper from a cigarette packet

My boss complained once that he was sick of blowing the
1A fuse in his car stereo. "It works OK for a while but then the
stereo crackles and the fuse goes". So he stuck a 40A head-
light one in. Just before he had to start shopping around for
a new stereo

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2003\03\14@212430 by Herbert Graf

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> Haha, like guitarists that stuff the fuseholder with silver
> paper from a cigarette packet
>
> My boss complained once that he was sick of blowing the
> 1A fuse in his car stereo. "It works OK for a while but then the
> stereo crackles and the fuse goes". So he stuck a 40A head-
> light one in. Just before he had to start shopping around for
> a new stereo

       A question in an exam at a local theatre technician school went something
like this:

You are in the middle of a show. The follow spot is plugged into a 115V
outlet, the only outlet anywhere within reach. All of a sudden the light
goes out. Fortunately the follow spot was masked at the time, however it
will be used within about 2 minutes. A quick check reveals the fuse for the
circuit has blown. A search reveals no available replacement. The only
things available are a penny and a nickel. Which would you use to restore
power to the circuit?

The answer?


NEITHER!!! Find out why the fuse blew! :) Good question, many get it wrong.
TTYL

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2003\03\15@061827 by Philip Pemberton

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Ned Konz wrote:
> Isn't Radio Shack's motto something like:
>
> Radio Shack: you've got questions, we've got blank looks.
"You've got questions, we've got blank stares"
OTOH, I did get some reasonably priced resistor packs from Radioshack - far
cheaper than anything I've seen over here in the UK...

Later.
--
Phil.
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2003\03\15@062451 by Philip Pemberton

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Benjamin Bromilow wrote:
> Carphone Whorehouses :) Where I live in Nottingham, Maplins are right
> next to PC World. It appears Maplins is slowly turning into it's
> neighbour. If you want a new mouse of some CD-Rs, no problems.
[snip]
There are advantages to living near the Farnell Electronics trade counter.
#5 minimum order for cash sales, #10 for credit cards IIRC. And they haven't
adopted the RS (RadioSpares - rshttp://www.com) "You NEED a trade account to
order" philosophy. Yet. I actually tried to order a few oddball parts from
RS not too long ago - STV5730s IIRC. RS: "That'll be #47.18"
Me: "WHAT???"
RS: "#34.19. #21.20 for the parts, #12.99 P&P"
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2003\03\15@062918 by Philip Pemberton

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'Scuse me - an unfinished message escaped. Time to turn off Keyboard
Shortcuts in Outlook...

Benjamin Bromilow wrote:
> Carphone Whorehouses  Where I live in Nottingham, Maplins are right
> next to PC World. It appears Maplins is slowly turning into it's
> neighbour. If you want a new mouse of some CD-Rs, no problems.
[snip]
There are advantages to living near the Farnell Electronics trade counter.
#5 minimum order for cash sales, #10 for credit cards IIRC. And they haven't
adopted the RS (RadioSpares - rshttp://www.com) "You NEED a trade account to
order" philosophy. Yet. I actually tried to order a few oddball parts from
RS not too long ago - STV5730s IIRC. RS: "That'll be #34.19"
Me: "WHAT???"
RS: "#34.19. #21.20 for the parts, #12.99 P&P"
Me: "Uh, I think I'll cancel that order. Thanks anyway."

Despite what they say, it DOES NOT cost #12.99 to send a Jiffy bag with two
components in a Corstat box via Royal Mail 1st Class. I've had stuff sent by
Farnell via Securicor Omega and it hasn't cost that much!

Later.
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2003\03\15@064149 by Philip Pemberton

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Alex Kilpatrick wrote:
> Are you sure?  My meter (Fluke) has two possible inputs for measuring
> current.  One goes up to 10A (I think) and one is fused at 100 mA.  If
> it isn't fast enough to save the electronics, then what is it for?
The fuses used in my Fluke 25 are listed on the back panel as follows:
F 630mA 250V
F 3A 600V
F 15A 600V

It looks like the 630mA is a miniature 20mm, the other two are HUGE (about
an inch or so in length). Now if only I had a copy of the manual for this
beast... Then again, it looks like the '25 is a '27 with a few features
removed. Natch. And with a repair/calibration pricetag of #120...

Later.
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2003\03\15@200711 by Alex Kilpatrick

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> Alex Kilpatrick wrote:
> > Are you sure?  My meter (Fluke) has two possible inputs for
> measuring
> > current.  One goes up to 10A (I think) and one is fused at
> 100 mA.  If
> > it isn't fast enough to save the electronics, then what is it for?
> The fuses used in my Fluke 25 are listed on the back panel as
> follows: F 630mA 250V F 3A 600V F 15A 600V
>
> It looks like the 630mA is a miniature 20mm, the other two
> are HUGE (about an inch or so in length). Now if only I had a
> copy of the manual for this beast... Then again, it looks
> like the '25 is a '27 with a few features removed. Natch. And
> with a repair/calibration pricetag of #120...
>
Well, in mine it is definitely 100 mA (it says so on the front panel).
It is a 5x20mm fuse.  I found them (after much hunting) at Fry's.

Alex

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