Searching \ for 'Actual Uses of Zero Ohm Resistor' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=actual+uses+zero
Search entire site for: 'Actual Uses of Zero Ohm Resistor'.

Truncated match.
PICList Thread
'Actual Uses of Zero Ohm Resistor'
1996\10\11@100502 by myke predko

flavicon
face
Hi Folks,

Before anybody says "It's a joke, Predko.  Lighten up.", I just wanted to
say that I've been involved with Zero-Ohm resistors for years.

The first time was when I was a student doing my first programming job in
the factory writing the code for taking component placement data out of a
"RIT" (Release Information Tape - yes it was a tape.  Now, it would be
called a Neutral File) and programming an Axial-Lead Sequencers.  An
Axial-Lead Sequencer is a machine that takes a whole bunch of different
Axial-Leaded (ie standard Resistors) punches them out of the tape they come
in and put them in a new tape, which is used to build the product.  This
way, the Axial-Lead insertion tool can be a lot simpler because it only
requires one tape input.

Surprisingly enough, this method of doing Axial-Leads (Radials are done with
a separate tape for each component) works really well - although you have to
have special procedures to make sure the tape doesn't get out of
synchronization (the importance of this will be obvious below).

The first time I was running my program from the RIT input, a number of
Zero-Ohm resistors were called out.  I asked about them and was told that
Zero-Ohm resistors were used all the time to program values/machine states
and models.

You have to remember that this was IBM in the late seventies and they were
really paranoid about people reverse engineering their products.  This meant
that all the "standard" parts (ie standard logic and TTL) were marked with
IBM, rather than industry standard, Part Numbers and (this always blew me
away) all passives (ie resistors) were completely unmarked.  To be fair, we
weren't religeous on the unmarked passives all the time (they cost 100x what
their marked cousins did - yes, 1/4 watt resistors cost about 75 cents each
in quantity!).

Zero-Ohm resistors (an encapsulated wire - we X-Rayed one just to see what
it actually was in it) looked exactly like all the other resistors on the
board.  If you care (probably not at this point), the PC was the first IBM
product that used Industry-Standard Marked Parts.

Now, if Zero-Ohm resistors are required, we use "Solder Interconnect
Technology" which is a fancy way of describing two SMT pads in very close
proximity in which solder paste is applied (before SMT reflow) between them
to make the short/Zero-Ohm connection.

Having gone through all this, what really blew me away was IBM's audacity in
the whole situation.  For those of you that remember the 5250 Terminal,
there was the standard english version which, in 1978, cost $4,000 and the
Kanji (Japanese) version that cost over $50,000.  What do you think the
difference was between the two terminals?

One Zero-Ohm resistor.

Sorry for the long note,

Myke

Do you ever feel like an XT Clone caught in the Pentium Pro Zone?

1996\10\11@130126 by Mike Riendeau

flavicon
face
    I have used zero ohm resistors in boards (including ones that
    use PICs) to save cost in laying the board out as a single sided
    PCB.  Single sided PCBs are much cheaper than double sided.
    The zero ohm resistors come in handy as jumpers to compensate for
    the lack of the top side routing; Because  they lend themselves
    to automatic insertion.

                                       Mike

1996\10\11@192328 by Eric Smith

flavicon
face
> Before anybody says "It's a joke, Predko.  Lighten up.", I just wanted to
> say that I've been involved with Zero-Ohm resistors for years.

It would be stretching things for me to say "involved with", but my story
about obtaining a box of them marked black-black-black-silver was true.  I
still have the box, buried somewhere in my storage locker.

And I did test one of them to prove it was out of tolerance.  My portable
multimeter was inadequate, so I had to borrow a high-end HP 6 1/2 digit
bench meter to test it.

I would have been really happy if they had met spec; it's not every day that
someone gives me a box of room-temperature superconductors.

Cheers,
Eric

1996\10\11@223243 by Robert Lunn

flavicon
face
> For those of you that remember the 5250 Terminal,
> there was the standard english version which, in 1978, cost $4,000
> and the Kanji (Japanese) version that cost over $50,000.  What do
> you think the difference was between the two terminals?
>
> One Zero-Ohm resistor.

       Used to call this the 'golden screwdriver' trick.

       Story was that DEC had two hard disk drives, one 10Mb
       and one 20Mb.  You could get a field upgrade from one
       to the other.  Technician would come out and (while
       you weren't looking ;) ) insert a long screwdriver in
       to the drive's guts and... flick a switch.

___Bob

1996\10\11@224457 by Robert Lunn

flavicon
face
>     I have used zero ohm resistors in boards (including ones that
>     use PICs) to save cost in laying the board out as a single sided
>     PCB.  Single sided PCBs are much cheaper than double sided.
>     The zero ohm resistors come in handy as jumpers to compensate for
>     the lack of the top side routing; Because  they lend themselves
>     to automatic insertion.

       ...thump <ouch>

___Bob

1996\10\14@053132 by William Sadler

flavicon
face
On 11 Oct 96 at 16:22, Eric Smith wrote:

>
>And I did test one of them to prove it was out of tolerance.  My portable
>multimeter was inadequate, so I had to borrow a high-end HP 6 1/2 digit
>bench meter to test it.

If it has any resistance, at all, it will be out of spec! :-(

ie. 0 Ohms +/- any % = 0 Ohms!


--
 William Sadler                MailTo:spam_OUTwillTakeThisOuTspamcocoa.cossor.com
 Network Administrator         Cossor Electronics
 Phone: UK(44) 1279 407025     Fax: UK(44) 1279 407384
--

1996\10\14@111048 by Stuart

flavicon
picon face
Eric wrote:

> It would be stretching things for me to say "involved with", but my
> story about obtaining a box of them marked black-black-black-silver
> was true.  I still have the box, buried somewhere in my storage
> locker.
[..]
> I would have been really happy if they had met spec; it's not every
> day that someone gives me a box of room-temperature superconductors.

Don't the manufacturers get silly with the banding and say something
like "For R < 100Ohm, gold=5% or +-0.1Ohm, whichever is the larger"?

If so, could you test your batch thoroughly and please send me the ones
that are at the negative end of the tolerance range?

Thanks  ;-)


Stuart.
--
Stuart Tyrrell                       .....StuartKILLspamspam@spam@stdevel.demon.co.uk
Stuart Tyrrell Developments          Hardware/Software design & support
PO Box 183, OLDHAM. OL2 8FB          ** New PS2Mouse interface available **
Orange: 0976 255 256 (SMS welcome)   http://www.stdevel.demon.co.uk

1996\10\14@144924 by Eric Smith

flavicon
face
> If it has any resistance, at all, it will be out of spec! :-(
> ie. 0 Ohms +/- any % = 0 Ohms!

That was my point.  My portable meter read 0.000 Ohms, but the 6 1/2 digit
HP bench meter showed that it was actually around 0.00004.

Cheers,
Eric

More... (looser matching)
- Last day of these posts
- In 1996 , 1997 only
- Today
- New search...