Parts values on schematic question

So why are small resistors marked?

Our AOI can check ICs and resistors for correct part, but not ceramic caps.

John Larkin wrote in news: snipped-for-privacy@4ax.com:

Below 0603?

I learn to properly set up, test and run my pick and place machines, and then to trust that the right parts got placed where they were supposed to be placed.

On protos I can see and rememeber slight differences between purchased caps, especially NPO or other substrate or uniquie element of their construction or appearance. HV SMD caps, for instance, have a different appearance to the overglaze.

Good for you!! If it ain't broke...

ave

es

tric a long time ago.

nd I thought half a pint, a cup, is not much beer or even orange juice (oft en served in tiny glasses in breakfast restaurants here). But a half pint in GB is 10 ounces which is nearly a 12 oz can of beer here. Now I have mu

ce cream in 20 oz pints!

As a kid I learned a pint's a pound the world around.. and then that it's only true in the US. How big is a (beer) pint in Canada?

George H.

Ethanol only, unlike in India.

We certainly like our beer to have a taste (cf Coors).

When I was there, it was Imperial all the way. I don't think the US system was ever used in Canada except by folks manufacturing for export.

Cheers

Phil Hobbs

Wouldn't that be 4u7?

Wouldn't that be 299m8/s?

Maybe you would if it was on a schematic in small print. How big do you make your decimal points?

Of course. My brain farted.

Got it! Thanks.

Only on a schematic.

"Big" is meaningless on a screen that can zoom any amount.

When we print schematics it's B size on a laser printer, and everything is clear and legible. The part values may not even be right, because we have dash-number versions of various products, and ECOs. The BOM is what's definitive.

The BOM for an assembly, based on reference designator, calls out a stock number for a part, and the inventory database has the value. And it does not show "4k99" as the value; it uses proper SI notation.

Good grief, if a decimal point somehow slipped off a schematic and got lost in the carpet, you'd see

instead of

and that should get your attention.

(I'm the only person in the company who still draws schematics on paper; everybody else enters directly with CAD, so can't lose decimal points. I don't lose them either because I know how to draw.)

Maybe we should have a special symbol for . when we type manuals too# That way, we wouldn't have to worry about losing periods and creating run-on sentences# Let's all do that#

Look at the post subject. That was the original question, was it not?

One would think but, no, it's "4R7". Neat, huh?

Wouldn't that be 299M8 m/s?

We don't use nF. Our schematics do indeed use "0.01uF". That's the divide between 'pF' and 'uF'. Less than 0.01uF, capacitors are in pF. Interestingly, everyone I know uses '3V3' sorts of notation to designate voltages (may be '3V3D' for a digital supply, '3V3A' for an analog supply, or '3V3Batt' for battery powered, or whatever).

Oh, I'm a physicist and respect myself. ;-)

r, as it avoids dot deterioration causing errors. Naturally paper data is l ess common now, but still in widespread use. It's not a new system. We use the method on printed paper that is liable to degrade in use. It's much mor e of an issue in the developing world.

If you saw the conditions people often operate in in the developing world y ou'd realise it has nothing to do with paranoia.

NT

Neither method is necessary. Your opinion on ugliness is simply your personal taste. There are multiple standards for various things, and in many cases no-one to enforce them, so it's inevitable that many are seen in practice. It's a complete non-problem.

I'll never forget when most seemed to think that marking power lines as Vcc and Vee was the only correct way. I never saw much sense in either that convention nor the insistence that it was somehow the only correct one and must be used.

Caps in Farads? You must look at different schematics to me. IME it nearly always means uF, sometimes pF, only seldom farads.

NT

there are a lot of wacky views on this topic.

yup

Both, until trading standards started prosecuting for selling in imperial. That peed off an awful lot of people. It's still common to see imperial but the law requires metric too.

Both imperial & metric.

NT

sounds messy.

NT

I thought half a pint, a cup, is not much beer or even orange juice (often served in tiny glasses in breakfast restaurants here). But a half pint in GB is 10 ounces which is nearly a 12 oz can of beer here. Now I have much

cream in 20 oz pints!

NT