Silly resistor values

I just checked some wired 330k 1% resistors from my stock and the average value was around 329k5.

I checked SMT 330k 1% resistors from Panasonic and Neohm and got 329k5 and

All the 330k 1% resistors I have were made as 330k resistors not 332k.

If you shipped 332k as 330k you waste 2/3rds of your tolerance and would have to manufacture and test to 0.3%.

Please don't quote out of context. This may be why you did not understand what I wrote.

I was talking about _specialty_ resistors, not run of the mill stuff. You may not have been involved in cost critical designs but many of us must occasionally turn every penny on a design.

Huh? One example out of a bazillion:

If the link breaks it's Vishay P/N VR25000002005KA100. And there's more where that came from ;-)

Hint: Occasionally it is very educational to open a rock-bottom priced gizmo with a phenolic board in there and take a look what's on that board. You'll be surprised.

Pay attention, Joerg... you're debating NymNoNuts.

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Not from any of the reputable manufacturers/distributors you won't.

Well, maybe if they know their 332k resistors are really 0.4%, in which case it could be substituted... although it'd still be a sleazy practice.

TAT-7 sounds like an interesting project, good old coax. Are you doing a lot of fiber-optics stuff nowadays?

I would flag that in a design review. 330K is not part of the E96 series, 332K is.

Well you sure don't have a proper "big company attitude" yet, do you? Where do you suppose all those transistor types came from or all those tube numbers before that? Why use a standard ANYTHING when you can change whatever it is just enough that the standard one won't work in your product anymore and force everyone to come to you for the parts (with you setting the price, natch).

The idea is always use custom components that are given company part numbers even when they are standard parts! All parts should always be referred to on schematics by ONLY a company part number. The link between any E24 resistors and the company part number (parts should ONLY bear a part number, never anything else that may give away what it actually is) should only be found in highly confidential part specifications indexed only by part numbers and not distributed to anyone in or outside the company. This secrecy outside the company is called "extra profit" and inside the company it's called "job security".

I hope you finally start to get it.

I smell Mickysoft tactics !

Tektronix has done that forever. They have internal part numbers for transistors, diodes, resistors, etc. At least they list equivalents where possible though (e.g., 2N3904).

I suppose Tektronix is the electronic Microsoft: dominated the quality market for a while, then sold out to crummy equipment and products? ;-)

Tim

Tek's motto used to be, "Committed to excellence."

Now it's "Enabling innovation."

Hmm, OK, but I really think the old one was a stronger statement...

Anyone have a list of company mottos over the years? I would imagine Tek had more than the two I've listed here, HP must have had a bunch, etc...

No. That is not the reason.

Yet you have no understanding of decades and why the values are what they are.

I have been working in the industry for 35 years. I do not think that ANY resistor value hinders ANYONE in both manufacturing or design.

Anyone that does have a problem with something so petty should not be working in the industry, much less in a design capacity.

No. An abject idiot, however, IS a nuisance.

Which costs more, uses up more precious PCB real estate, and is MORE DIFFICULT to implement. Combining parts to create a value of resistance when a single part is available is an order of magnitude more stupid.

Your company's lethargic, poorly stocked "system"?

The 'standard values' ARE in "the system" The system that the entire rest of the world uses. D'oh!

I suggest you modify your "system" as well as your mindset.

You are only making things more difficult for yourself, trying to re-think what the entire industry has already hashed over to oblivion will not get you there.

really

their

nice

He listed tolerances for the mil parts, but left out the tempco's?

Oh, and there are 6 band striped axial parts out there as well.

Wink all you want, dumbass. That is a multi-megohm part. It is also a bulk form power resistor. In fact ALL of them are either high voltage or power resistors.

Now go find standard values and standard packaging, like SMT that are less than 1Mohm. You know... part that we all DO use, not some obscure crap (which I already was aware of).

Get back to me when you find even one.

Utter nonsense.

A 1/4 watt resistor is a "bulk form power resistor"? ROFL!

You wrote, quote "but you cannot even find 10% resistors in axial", and I found you one.

Have you ever opened such stuff? Like X-10 modules, toys, remotes, cheap radio controls? I guess not ...

Question: did you even bother to look around? This whole series comes in

So, there :-)

What's next? That it must be RoHS? Rest assured, they are.

No, idiot. The one you posted a link to was a 5 watt power resistor.

And, as I stated, it is a High Voltage Resistor.

You did not read what I wrote. These are not standard, everyday parts, they are purpose specific.

I know what it smells like when it burns (the PCB media), so that alone should tell you enough. That memory originally dates back to the late sixties. Of course subsequent events indicates further experience.

Answer: I have some experience in electronics manufacturing, including the use of bulk media (not count, material of construction) and high voltage types of resistors. I have seen a large array of what can be expected in resistors. I am sure there are those I have not seen. I have seen resistors that stop trains.

They are not as cheap as you might think. Those are "pulse withstanding" thick film devices, and I'll bet that they ALL cost more then the std Vishay stuff in the local catalogues.

So, maybe you should look closer... and again.

Piss on RoHS, I am exempt. I don' need no stinkin' compliance badges...

average

and

Sorry about the typo i meant 330k 10%

That is part of the point i was making.

I left that world behind when I left STC. I never got involved with fibre though STC were working on it.

The high rel requirement led to conservative design approaches. PCBs were only just being introduced in 1976, everything before then was made on custom tag boards with tags mounted on perspex. The fear was that chemicals could leach out of the pcbs over 25 years in a sealed environment and lead to corrosion and failure. Even the resistors were unmarked so that the paint dyes could not leach out.

Looking at the responses it is clear that E96 resistors are considered standard in the US. In my experience that is not the case here in the UK.