Reply by Michael Schwingen●November 13, 20222022-11-13
On 2022-11-13, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
>
> A microcontroller has to be programmed, which has its own costs. And
> it still needs guaranteed clean powerup and powerdown and a regulator
> down from the 12/24 volt prime supply.
The LM3880 also needs a regulated 5V supply. Programming is done by the
distributor before assembly (yes, that costs some additional cents).
> A reel of LM3880's cost us 44 cents each, not even rounding error on
> product price.
I was quoted similar prices for STM32G030 back before they went unobtainium
... we now use GD32. The microcontroller does system management including
temperature and fan control, and protects the main CPU even if it locks up
hard and overheats.
cu
Michael
Reply by John Larkin●November 13, 20222022-11-13
On Sun, 13 Nov 2022 13:32:08 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>John Larkin wrote:
>> On Sat, 12 Nov 2022 18:21:42 -0500, Joe Gwinn <joegwinn@comcast.net>
>> wrote:
>>
>>> On Sat, 12 Nov 2022 14:50:59 -0800, John Larkin
>>> <jlarkin@highlandSNIPMEtechnology.com> wrote:
>>>
>>>> On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>>
>>>>> John Larkin wrote:
>>>>>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>>>>>
>>>>>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>>>>>> flathead screws cut into anodized countersinks pretty well.
>>>>>>>
>>>>>>> They make a reliable ground if you use these washers
>>>>>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>>>>>> making a gas-tight contact. For power safety ground, of course,
>>>>>>> you want a connection OTHER than a fastener that can be loosened from outside
>>>>>>> the box (like, a rivet, or externally-unreachable screwdown).
>>>>>>
>>>>>> I could get some to try, but I think they would look klunky on an
>>>>>> external end plate. People already are whining about the undercut
>>>>>> flatheads, which extend maybe 20 mils above the panel.
>>>>>>
>>>>>> These little boxes are powered from warts and usually bolted down, so
>>>>>> we don't need a big ground lug.
>>>>>>
>>>>>
>>>>> So you're using a thin head that's flat top and bottom to cut into the
>>>>> conical surface?
>>>>>
>>>>> ("Flat head screw" means countersunk in my lexicon, as opposed to (for
>>>>> example) the painted oval head things that come packaged with outlet
>>>>> plates from Home Depot.)
>>>>>
>>>>> Cheers
>>>>>
>>>>> Phil Hobbs
>>>>
>>>> Looks like a regular flathead, but undercut below.
>>>>
>>>> https://www.newportfasteners.com/10-32-x-1-4-machine-screws-phillips-flat-undercut-head-steel-zinc-plating-quantity-100-pcs.html?gclid=EAIaIQobChMIyc6f29up-wIVsClMCh3eIAyoEAQYASABEgK1rvD_BwE
>>>>
>>>> (We're using 6-32 and metric on various boxes.)
>>>>
>>>> Undercut is normally used to keep the screw from bottoming on the box
>>>> and making the thin end plate get loose, but the sharp edge also cuts
>>>> into the anodized countersink and makes a good ground.
>>>
>>> Ahh. I wondered what exactly was being used. It's called a "flat
>>> undercut" head.
>>>
>>> .<https://www.newportfasteners.com/fastener-guides/screws-head-styles.html>
>>>
>>>
>>
>> My mistake for calling it "undercut flathead" instead of "flathead
>> undercut."
>>
>>
>>>> A regular flathead screw in an anodized countersink can be iffy
>>>> electrically. Parallel rubbing surfaces.
>>>
>>> I'd put a drop of Noalox on the screw before installation, covering
>>> both the threaded part and the underside of the screw head.
>>>
>>> Noalox will also act as an anti-seize compound.
>>>
>>> .<https://www.idealind.com/us/en/shop/30-026.html>
>>>
>>> Available at Lowes, Home Depot, et al.
>>>
>>>
>>> Joe Gwinn
>>
>> Some of this is clean-room gear. Zinc particles might not be welcome.
>>
>
>In the tool core rather than the fab side of the wall, right?
>
>Cheers
>
>Phil Hobbs
This particular box is used in the sub-fab, the light source a floor
below the wafer fab, and in the wafer area itself.
We have an elaborate ritual where we clean each box in a laminar flow
hood and triple-bag each one.
The old Hammond boxes used self-tapping screws and liked to strew
metal shavings, which usually stayed inside the boxes.
Reply by Phil Hobbs●November 13, 20222022-11-13
John Larkin wrote:
> On Sat, 12 Nov 2022 18:21:42 -0500, Joe Gwinn <joegwinn@comcast.net>
> wrote:
>
>> On Sat, 12 Nov 2022 14:50:59 -0800, John Larkin
>> <jlarkin@highlandSNIPMEtechnology.com> wrote:
>>
>>> On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>
>>>> John Larkin wrote:
>>>>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>>>>
>>>>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>>>>> flathead screws cut into anodized countersinks pretty well.
>>>>>>
>>>>>> They make a reliable ground if you use these washers
>>>>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>>>>> making a gas-tight contact. For power safety ground, of course,
>>>>>> you want a connection OTHER than a fastener that can be loosened from outside
>>>>>> the box (like, a rivet, or externally-unreachable screwdown).
>>>>>
>>>>> I could get some to try, but I think they would look klunky on an
>>>>> external end plate. People already are whining about the undercut
>>>>> flatheads, which extend maybe 20 mils above the panel.
>>>>>
>>>>> These little boxes are powered from warts and usually bolted down, so
>>>>> we don't need a big ground lug.
>>>>>
>>>>
>>>> So you're using a thin head that's flat top and bottom to cut into the
>>>> conical surface?
>>>>
>>>> ("Flat head screw" means countersunk in my lexicon, as opposed to (for
>>>> example) the painted oval head things that come packaged with outlet
>>>> plates from Home Depot.)
>>>>
>>>> Cheers
>>>>
>>>> Phil Hobbs
>>>
>>> Looks like a regular flathead, but undercut below.
>>>
>>> https://www.newportfasteners.com/10-32-x-1-4-machine-screws-phillips-flat-undercut-head-steel-zinc-plating-quantity-100-pcs.html?gclid=EAIaIQobChMIyc6f29up-wIVsClMCh3eIAyoEAQYASABEgK1rvD_BwE
>>>
>>> (We're using 6-32 and metric on various boxes.)
>>>
>>> Undercut is normally used to keep the screw from bottoming on the box
>>> and making the thin end plate get loose, but the sharp edge also cuts
>>> into the anodized countersink and makes a good ground.
>>
>> Ahh. I wondered what exactly was being used. It's called a "flat
>> undercut" head.
>>
>> .<https://www.newportfasteners.com/fastener-guides/screws-head-styles.html>
>>
>>
>
> My mistake for calling it "undercut flathead" instead of "flathead
> undercut."
>
>
>>> A regular flathead screw in an anodized countersink can be iffy
>>> electrically. Parallel rubbing surfaces.
>>
>> I'd put a drop of Noalox on the screw before installation, covering
>> both the threaded part and the underside of the screw head.
>>
>> Noalox will also act as an anti-seize compound.
>>
>> .<https://www.idealind.com/us/en/shop/30-026.html>
>>
>> Available at Lowes, Home Depot, et al.
>>
>>
>> Joe Gwinn
>
> Some of this is clean-room gear. Zinc particles might not be welcome.
>
In the tool core rather than the fab side of the wall, right?
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttp://hobbs-eo.com
Reply by Joe Gwinn●November 13, 20222022-11-13
On Sat, 12 Nov 2022 18:19:53 -0800, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:
>On Sat, 12 Nov 2022 18:21:42 -0500, Joe Gwinn <joegwinn@comcast.net>
>wrote:
>
>>On Sat, 12 Nov 2022 14:50:59 -0800, John Larkin
>><jlarkin@highlandSNIPMEtechnology.com> wrote:
>>
>>>On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
>>><pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>
>>>>John Larkin wrote:
>>>>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>>>>
>>>>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>>>>> flathead screws cut into anodized countersinks pretty well.
>>>>>>
>>>>>> They make a reliable ground if you use these washers
>>>>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>>>>> making a gas-tight contact. For power safety ground, of course,
>>>>>> you want a connection OTHER than a fastener that can be loosened from outside
>>>>>> the box (like, a rivet, or externally-unreachable screwdown).
>>>>>
>>>>> I could get some to try, but I think they would look klunky on an
>>>>> external end plate. People already are whining about the undercut
>>>>> flatheads, which extend maybe 20 mils above the panel.
>>>>>
>>>>> These little boxes are powered from warts and usually bolted down, so
>>>>> we don't need a big ground lug.
>>>>>
>>>>
>>>>So you're using a thin head that's flat top and bottom to cut into the
>>>>conical surface?
>>>>
>>>>("Flat head screw" means countersunk in my lexicon, as opposed to (for
>>>>example) the painted oval head things that come packaged with outlet
>>>>plates from Home Depot.)
>>>>
>>>>Cheers
>>>>
>>>>Phil Hobbs
>>>
>>>Looks like a regular flathead, but undercut below.
>>>
>>>https://www.newportfasteners.com/10-32-x-1-4-machine-screws-phillips-flat-undercut-head-steel-zinc-plating-quantity-100-pcs.html?gclid=EAIaIQobChMIyc6f29up-wIVsClMCh3eIAyoEAQYASABEgK1rvD_BwE
>>>
>>>(We're using 6-32 and metric on various boxes.)
>>>
>>>Undercut is normally used to keep the screw from bottoming on the box
>>>and making the thin end plate get loose, but the sharp edge also cuts
>>>into the anodized countersink and makes a good ground.
>>
>>Ahh. I wondered what exactly was being used. It's called a "flat
>>undercut" head.
>>
>>.<https://www.newportfasteners.com/fastener-guides/screws-head-styles.html>
>>
>>
>
>My mistake for calling it "undercut flathead" instead of "flathead
>undercut."
Yes; I was citing the standard term, versus a description. In this
case, both terms would work for google, but that is often not the
case.
>>>A regular flathead screw in an anodized countersink can be iffy
>>>electrically. Parallel rubbing surfaces.
>>
>>I'd put a drop of Noalox on the screw before installation, covering
>>both the threaded part and the underside of the screw head.
>>
>>Noalox will also act as an anti-seize compound.
>>
>>.<https://www.idealind.com/us/en/shop/30-026.html>
>>
>>Available at Lowes, Home Depot, et al.
>>
>>
>>Joe Gwinn
>
>Some of this is clean-room gear. Zinc particles might not be welcome.
For clean rooms, probably not. What fraction of the users would this
be?
If necessary, there is a trick. After seating the zinc particles in
the aluminum with a screw used only for that (or a conical tool
pressed from above), wash the alnox off with solvent and assemble
using a clean screw. The zinc particles should largely be trapped in
the aluminum. I don't know if this is good enough for those clean
rooms.
Joe Gwinn
Reply by John Larkin●November 13, 20222022-11-13
On 13 Nov 2022 10:43:23 GMT, Michael Schwingen
<news-1513678000@discworld.dascon.de> wrote:
>On 2022-11-11, olaf <olaf@criseis.ruhr.de> wrote:
>>
>> >https://www.dropbox.com/sh/gxvkrjd0fr7peft/AACsNPaUkMTtTOAVcS1qeJAna?dl=0
>>
>> I am impressed by the LM3880. I did not know that something
>> like this exist.
>
>Hm - yes, nice, but at a price where I can get a small microcontroller which
>will do other tasks at the same time.
>
>cu
>Michael
A microcontroller has to be programmed, which has its own costs. And
it still needs guaranteed clean powerup and powerdown and a regulator
down from the 12/24 volt prime supply.
We have a 400-ball Zynq do do any computing that we need.
A reel of LM3880's cost us 44 cents each, not even rounding error on
product price.
Reply by Michael Schwingen●November 13, 20222022-11-13
Hm - yes, nice, but at a price where I can get a small microcontroller which
will do other tasks at the same time.
cu
Michael
Reply by John Larkin●November 12, 20222022-11-12
On Sat, 12 Nov 2022 18:21:42 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:
>On Sat, 12 Nov 2022 14:50:59 -0800, John Larkin
><jlarkin@highlandSNIPMEtechnology.com> wrote:
>
>>On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
>><pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>>John Larkin wrote:
>>>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>>>> wrote:
>>>>
>>>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>>>
>>>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>>>> flathead screws cut into anodized countersinks pretty well.
>>>>>
>>>>> They make a reliable ground if you use these washers
>>>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>>>> making a gas-tight contact. For power safety ground, of course,
>>>>> you want a connection OTHER than a fastener that can be loosened from outside
>>>>> the box (like, a rivet, or externally-unreachable screwdown).
>>>>
>>>> I could get some to try, but I think they would look klunky on an
>>>> external end plate. People already are whining about the undercut
>>>> flatheads, which extend maybe 20 mils above the panel.
>>>>
>>>> These little boxes are powered from warts and usually bolted down, so
>>>> we don't need a big ground lug.
>>>>
>>>
>>>So you're using a thin head that's flat top and bottom to cut into the
>>>conical surface?
>>>
>>>("Flat head screw" means countersunk in my lexicon, as opposed to (for
>>>example) the painted oval head things that come packaged with outlet
>>>plates from Home Depot.)
>>>
>>>Cheers
>>>
>>>Phil Hobbs
>>
>>Looks like a regular flathead, but undercut below.
>>
>>https://www.newportfasteners.com/10-32-x-1-4-machine-screws-phillips-flat-undercut-head-steel-zinc-plating-quantity-100-pcs.html?gclid=EAIaIQobChMIyc6f29up-wIVsClMCh3eIAyoEAQYASABEgK1rvD_BwE
>>
>>(We're using 6-32 and metric on various boxes.)
>>
>>Undercut is normally used to keep the screw from bottoming on the box
>>and making the thin end plate get loose, but the sharp edge also cuts
>>into the anodized countersink and makes a good ground.
>
>Ahh. I wondered what exactly was being used. It's called a "flat
>undercut" head.
>
>.<https://www.newportfasteners.com/fastener-guides/screws-head-styles.html>
>
>
My mistake for calling it "undercut flathead" instead of "flathead
undercut."
>>A regular flathead screw in an anodized countersink can be iffy
>>electrically. Parallel rubbing surfaces.
>
>I'd put a drop of Noalox on the screw before installation, covering
>both the threaded part and the underside of the screw head.
>
>Noalox will also act as an anti-seize compound.
>
>.<https://www.idealind.com/us/en/shop/30-026.html>
>
>Available at Lowes, Home Depot, et al.
>
>
>Joe Gwinn
Some of this is clean-room gear. Zinc particles might not be welcome.
Reply by Joe Gwinn●November 12, 20222022-11-12
On Sat, 12 Nov 2022 14:50:59 -0800, John Larkin
<jlarkin@highlandSNIPMEtechnology.com> wrote:
>On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
><pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>>John Larkin wrote:
>>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>>> wrote:
>>>
>>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>>
>>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>>> flathead screws cut into anodized countersinks pretty well.
>>>>
>>>> They make a reliable ground if you use these washers
>>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>>> making a gas-tight contact. For power safety ground, of course,
>>>> you want a connection OTHER than a fastener that can be loosened from outside
>>>> the box (like, a rivet, or externally-unreachable screwdown).
>>>
>>> I could get some to try, but I think they would look klunky on an
>>> external end plate. People already are whining about the undercut
>>> flatheads, which extend maybe 20 mils above the panel.
>>>
>>> These little boxes are powered from warts and usually bolted down, so
>>> we don't need a big ground lug.
>>>
>>
>>So you're using a thin head that's flat top and bottom to cut into the
>>conical surface?
>>
>>("Flat head screw" means countersunk in my lexicon, as opposed to (for
>>example) the painted oval head things that come packaged with outlet
>>plates from Home Depot.)
>>
>>Cheers
>>
>>Phil Hobbs
>
>Looks like a regular flathead, but undercut below.
>
>https://www.newportfasteners.com/10-32-x-1-4-machine-screws-phillips-flat-undercut-head-steel-zinc-plating-quantity-100-pcs.html?gclid=EAIaIQobChMIyc6f29up-wIVsClMCh3eIAyoEAQYASABEgK1rvD_BwE
>
>(We're using 6-32 and metric on various boxes.)
>
>Undercut is normally used to keep the screw from bottoming on the box
>and making the thin end plate get loose, but the sharp edge also cuts
>into the anodized countersink and makes a good ground.
>A regular flathead screw in an anodized countersink can be iffy
>electrically. Parallel rubbing surfaces.
I'd put a drop of Noalox on the screw before installation, covering
both the threaded part and the underside of the screw head.
Noalox will also act as an anti-seize compound.
.<https://www.idealind.com/us/en/shop/30-026.html>
Available at Lowes, Home Depot, et al.
Joe Gwinn
Reply by John Larkin●November 12, 20222022-11-12
On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>John Larkin wrote:
>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>> wrote:
>>
>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>
>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>> flathead screws cut into anodized countersinks pretty well.
>>>
>>> They make a reliable ground if you use these washers
>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>> making a gas-tight contact. For power safety ground, of course,
>>> you want a connection OTHER than a fastener that can be loosened from outside
>>> the box (like, a rivet, or externally-unreachable screwdown).
>>
>> I could get some to try, but I think they would look klunky on an
>> external end plate. People already are whining about the undercut
>> flatheads, which extend maybe 20 mils above the panel.
>>
>> These little boxes are powered from warts and usually bolted down, so
>> we don't need a big ground lug.
>>
>
>So you're using a thin head that's flat top and bottom to cut into the
>conical surface?
>
>("Flat head screw" means countersunk in my lexicon, as opposed to (for
>example) the painted oval head things that come packaged with outlet
>plates from Home Depot.)
>
>Cheers
>
>Phil Hobbs
On Sat, 12 Nov 2022 14:25:30 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>John Larkin wrote:
>> On Fri, 11 Nov 2022 23:23:47 -0800 (PST), whit3rd <whit3rd@gmail.com>
>> wrote:
>>
>>> On Friday, November 11, 2022 at 1:10:53 PM UTC-8, John Larkin wrote:
>>>
>>>> We do need to be careful that everything is solidly grounded. Undercut
>>>> flathead screws cut into anodized countersinks pretty well.
>>>
>>> They make a reliable ground if you use these washers
>>> <https://www.mcmaster.com/washers/countersunk-external-tooth-lock-washers/>
>>> making a gas-tight contact. For power safety ground, of course,
>>> you want a connection OTHER than a fastener that can be loosened from outside
>>> the box (like, a rivet, or externally-unreachable screwdown).
>>
>> I could get some to try, but I think they would look klunky on an
>> external end plate. People already are whining about the undercut
>> flatheads, which extend maybe 20 mils above the panel.
>>
>> These little boxes are powered from warts and usually bolted down, so
>> we don't need a big ground lug.
>>
>
>So you're using a thin head that's flat top and bottom to cut into the
>conical surface?
>
>("Flat head screw" means countersunk in my lexicon, as opposed to (for
>example) the painted oval head things that come packaged with outlet
>plates from Home Depot.)
Flat head is the correct term for the kind that goes flush in a
countersunk (conical) hole. The oval things have "oval" heads.
Here is the rest of the chart:
.<https://www.boltdepot.com/fastener-information/type-chart.aspx>
The bible for all such things is "Machinery's Handbook", first edition
published in 1914, and continuously ever since. Current is the 31st
edition.
.<https://books.industrialpress.com/9780831137311/machinerys-handbook-toolbox/>
There are lots of used copies available for small dollars in such as
used tool stores (and eBay).
Older editions are perfectly serviceable, especially for a small shop
with manual machines. I use the 27th edition, and also the 25th
edition.
The original size was meant to fit into the upper center drawer of a
standard machinist's 8-drawer toolbox, such as that made by Kennedy.
This size is now known as a "toolbox" edition, and it's larger version
is a "big-print" edition.
Joe Gwinn