Yes, and the mounting surfaces are ground flat, too. Any core with a central hole will have some inner-diameter inaccuracy that's hard to grind away, but mechanically, the precision of grinding can be much better than 1 mil (by a factor of twenty). You just don't need that, and it wouldn't be easy to mass-produce.
Why use a mill instead of a surface grinder? The mill seems worse in every way.
-- When I tried casting out nines I made a hash of it.
John Larkin isn't really into state-of-the-art engineering. He's into state-of-the-art-as-he-understands-it engineering, which isn't quite the same thing
1.5mm is a very large gap. The RM8 data sheet that I posted earlier in this thread had gaps up to 0.5mm at the centre but 1.5mm at the centre and the rim is 3mm of out-of ferrite gap, when the 38mm path through the ferrite looks like a 0.25mm air path.Transmission line transformers only use the core to get good coupling at low frequencies, but using the board as a gap would throw away a great deal of that.
-- Bill Sloman, Sydney
You can think what you like, and are clearly unconstrained by much real world knowledge. The point I was making was that "laser interferometry" is a rather broad term, and I did know quite a bit about one aspect of it.
Newton's rings came up rather earlier in my career, but you don't need a laser to see them - spray salt into a bunsen-burner flame and you can get enough sodium D-line emission to see them on the bench.
-- Bill Sloman, Sydney
Bill Sloman wrote in news: snipped-for-privacy@googlegroups.com:
No, it does not increase emission ANY great amount. Still falls in at 'negligible', and that even on the compliance terms. Nice try though, Billy.
You, out in the environment, is what is not a good idea. Do go the f*ck away.
If you want a precise inductance, you need a part you can trim. A "mirror finish" doesn't come into that.
You idea of what constitutes "precision" does seem to be rather vague.
-- Bill Sloman, Sydney
Bill Sloman wrote in news: snipped-for-privacy@googlegroups.com:
My God, Billy, you are an absolute idiot.
It is used for surface analysis as well, dipshit. And oh, look! THAT is what we were talking about, not your retarded spectral lines.
Relative to what?
But you have no idea how much. "Neglible" just means that you have got away with ignoring it, so far.
-- Bill Sloman, Sydney
of uses that the world has come up with for interferometric analysis and are only familiar with the state the art had when you were actually a little less senile than you are now.
Monochromatic sources make the interference fringes more obvious, which is what we are talking about, even if you are unaware of it.
-- Bill Sloman, Sydney
Bill Sloman wrote in news: snipped-for-privacy@googlegroups.com:
You are an idiot. All that matters is that it "still meets emissions compliance specs". Relative to that, dumbfuck.
Go look it up, asswipe. It leaks less than that. Numbers are not needed.
Bill Sloman wrote in news: snipped-for-privacy@googlegroups.com:
The zero crossing affect is what you know nothing about. That is switching losses unless managed, and the gapped core does that just fine.
You are clueless.
Actually, it doesn't. I spent more time minimising interference between seg ments on the same board than I ever did worrying about emissions compliance specfications. When buried ground and power planes got cheap enough, it be came less of a problem, but the kind of scientific instruments that I worke d on had a nasty habit of mixing sensitive analog bits with noisy power-sw itching bits.
Actually "leaks less than that" raises the question of "leaks less than wha t"?
Looking up something that you haven't bothered to specify would be difficul t.
If you can't even manage to spell out what you are talking about, it's fair ly clear that numbers don't matter to you because you haven't got any idea of what you might be measuring.
-- Bill Sloman, Sydney
Since you can't explain what you are talking about, the cluelessness is all yours.
-- Bill Sloman, Sydney
Bill Sloman wrote in news: snipped-for-privacy@googlegroups.com:
The compliance spec, you illiterate, retarded twit.
Which you haven't provided any kind of link to, so it's one more imaginary thing that you brandish as an alternative to saying anything meaningful.
-- Bill Sloman, Sydney
[about gapping a pot core with a layer of tape]
What the heck does 'compliance' have to do with it? It's the problem of flux escaping the core, which is otherwise self-shielding, and coupling to nearby items on the circuit board. Power radiated into antennae a few meters away is what the 'compliance' testing is about, and that's usually NOT the crosstalk issue that matters.
A wrap of copper tape around the gap at the rim, in any case, mostly restores the shielding (unless you want to put a can around it, which also works). It's a tad more elegant to USE the self-shielding property of the cores, though.
Self-shielding is a wonderful property, don't ruin it
whit3rd wrote in news:a49c7b08-cc90-4ccd-8203- snipped-for-privacy@googlegroups.com:
Except it doesn't (couple).
If your design is not saturating the core, and it shouldn't be, the leakage is minimal and negligible.
Unless you are so stupid as to place a component right up against it. Doh!
whit3rd wrote in news:a49c7b08-cc90-4ccd-8203- snipped-for-privacy@googlegroups.com:
I was referring to emissions compliance. Things the mil boys do.
Maybe you are unfamiliar.
whit3rd wrote in news:a49c7b08-cc90-4ccd-8203- snipped-for-privacy@googlegroups.com:
A can does, as they are usually steel. The tape will not unless you ground it, and no, you cannot assume the core is or that it will connect to the tape.
Until you need to gap one to condition curcuit performance.
Don't act like a pissy little bitch.
You are like the dope that thinks a word has only one meaning.
YES, IDIOT designs are made that utilze a gapped core and do so using the method I describe. Period.
You are like a goddamned Trumpanzee nitwit to think that since there is leakage that nobody does it or that it has no purpose. I have experience with factory core post gapped core sets, and I happen to know that more precise adjustment is done manually on ungapped core sets. And the manufacturers all concurr.
That is what happens when a developer gets on the phone with them to solve problems.
Please try not to be like the Trumpanzee retards.
Not only the military. In 1993 I had to take the IASys biosensor unit off to get it's emissions measured. We did sell one to Porton Down in the UK which was a germ warfare place, but most went into pathology labs.
The first version of the machine (which I tidied up no end) suffered because the front end was picking up the emissions from digital part of the machine (which included a Transputer, which was probably an overkill).
My tidy-up of the front end made it a lot less sensitive. Getting the digital part quiet could have been done, but would have been a lot more expensive.
-- Bill Sloman, Sydney
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