The mounting holes on PC motherboards: are they usually connected to the PCB ground plane?
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John Larkin Highland Technology Inc
Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
depends. Are you wearing them like you should ?:-) ...Jim Thompson
-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at
Yes.
L thought you have been claiming to have laid out PWAs for the last several years.
This is a no brainer.
If you had ever assembled your own PC at any time, you would know the answer simply by examining the fastener/stud pack that comes with the motherboard.
Decades. When I design stuff, I always bolt the pcb ground plane to the enclosure as many places as possible. But I don't know if pc mobos sometimes/never/always do that.
OK, answer the question.
I have never assembled my own house, car, refrigerator, TV, or PC. I buy them all done and tested. I have more than enough electronics of my own to design.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
You never actually say anything with content any more. You don't even discuss circuits in any intelligent way. You've become a useless old hen.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
how is the mounting HW going to tell you if the mounting holes are connected to the internal ground planes?
-Lasse
And your WORKING circuits are WHERE ?:-) ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
I have seen both, probably best to take a look at the board you've got. For example, this one appears to be heavily via'd to GND as I believe it should be:
-- Regards, Joerg http://www.analogconsultants.com/
A few are here:
Any your fast current source is where? You can't do it!
I rather liked the mosfet-bipolar cascode with Ib correction, but you didn't. What did you find wrong with it? I mean, aside from the fact that I invented it. Are you claiming that this *won't* work?
But I have a couple of better, cuter circuits by now. Show us your approach, and then I'll post a couple more of mine.
You never say anything substantive about electronics lately. You can't invent circuits any more. Go back to sci.electronics.basics where amateurs belong.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
hard to tell from the pic but I think it looks like there is isolation around the pad so it doesn't connect to the top layer, might not connect internally either
-Lasse
John Larkin Inscribed thus:
Yes, always ! Also don't use fibre washers under the screw heads.
--
Best Regards:
Baron.
Almost never IME. I constantly have to argue folks into doing it. Some have alternative approaches, e.g. a non-plated mounting hole surrounded by a wide pad containing a whole bunch of ground vias. That allegedly prevents the screw from damaging the plating.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
(Folks doing other sorts of boards, I mean.0
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
Usually, but not always! John Ferrell W8CCW
Examine the hole; the ones with 'stitched' multiple PTH around 'em are good grounds. Plated-through-hole with a mounting screw through it might get the in-hole plating damaged, so the connection to the inner vias is not otherwise reliable.
Unreliable or not, it's common practice to snap a plastic button into many (or most) of the mounting holes, and slide the buttons into slots, with only one or two mount holes (the ones near the external connectors) actually having conductive fastening hardware.
Your brilliance escapes any observation. Must all be super secret stuff.
I'll simplify the question for you, Mr. Electronics.
How could you ever think that it would be isolated?
Bullshit. You could not name even a single MOBO that has isolated mount holes. It world fail to comply with the spec, and no maker ever took that chance.
You are a liar. You have NOT "seen both".
Of course they ALL are, idiot. It is called a standard, and you ain't bright enough to know that the makers had to follow one?
How did you ever get a license to use radios?
You only need to use ONE metal stud. You CAN use them all, but you can also use nylon for all BUT ONE.
They are all tied to ground, but only one needs to be to properly install it into a case.
This assumes that the case is metallic, since some are not these days.
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