floating capacitance...

[server]

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.






--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Klaus Kragelund]

On Tuesday, October 13, 2020 at 5:43:56 AM UTC+2, jla...@highlandsniptechnology.com wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Nice way to use a component on the PCB for that function

 

[Mike Coon]

In article <ba8aofl9hjuhilp5hqvipv3sfat1r6bh6p@4ax.com>,
jlarkin@highlandsniptechnology.com says...

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Sort of like a Sesamoid bone?

 

[legg]

On Mon, 12 Oct 2020 20:43:44 -0700, jlarkin@highlandsniptechnology.com
wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Don\'t the body sizes shrink (from the vendor) with time?

RL

 

[Clive Arthur]

On 13/10/2020 04:43, jlarkin@highlandsniptechnology.com wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Should\'ve used one of these...

https://www.electronicsweekly.com/news/products/passives-products/detonators-go-surface-mount-2015-04/

--
Cheers
Clive

 

[Ricketty C]

On Tuesday, October 13, 2020 at 7:33:06 AM UTC-4, legg wrote:

On Mon, 12 Oct 2020 20:43:44 -0700, jlarkin@highlandsniptechnology.com
wrote:


This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Don\'t the body sizes shrink (from the vendor) with time?

The \"available\" sizes shrink. The height is part of the part number, so that part will always be the same.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[server]

On Mon, 12 Oct 2020 23:06:23 -0700 (PDT), Klaus Kragelund
<klauskvik@hotmail.com> wrote:

On Tuesday, October 13, 2020 at 5:43:56 AM UTC+2, jla...@highlandsniptechnology.com wrote:
This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Nice way to use a component on the PCB for that function

I wanted to use a copper circle, solder pasted, but production says
the solder is only 4 mils thick, 5 with the copper. It might dome up a
bit in the middle, but the cap is thickness is right and reliable.

I\'d use it as a bypass, but all my reasonable bypass values are 0805s.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[John Larkin]

On Tue, 13 Oct 2020 12:41:41 +0100, Clive Arthur
<clive@nowaytoday.co.uk> wrote:

On 13/10/2020 04:43, jlarkin@highlandsniptechnology.com wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Should\'ve used one of these...

https://www.electronicsweekly.com/news/products/passives-products/detonators-go-surface-mount-2015-04/

There are explosives that are, by design, very hard to detonate.
Exploding wires and the usual initiators won\'t work. What does work is
something like that, a thinfilm resistor with some kapton-like coating
that vaporizes and slaps really hard and fast.

 

[LM]

On Mon, 12 Oct 2020 20:43:44 -0700, jlarkin@highlandsniptechnology.com
wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

I feel pity for someone who tries figure out why that chip is there.

 

[John Larkin]

On Tue, 13 Oct 2020 23:25:31 +0300, LM <sala.nimi@mail.com> wrote:

On Mon, 12 Oct 2020 20:43:44 -0700, jlarkin@highlandsniptechnology.com
wrote:


This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.
I feel pity for someone who tries figure out why that chip is there.

Competitors. Spies. Good.

Maybe I should connect it to something to make it more confusing.

 

[legg]

On Tue, 13 Oct 2020 13:46:41 -0700, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Tue, 13 Oct 2020 23:25:31 +0300, LM <sala.nimi@mail.com> wrote:

On Mon, 12 Oct 2020 20:43:44 -0700, jlarkin@highlandsniptechnology.com
wrote:


This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.
I feel pity for someone who tries figure out why that chip is there.

Competitors. Spies. Good.

Maybe I should connect it to something to make it more confusing.

Patent immediately.

RL

 

[Don]

Mike Coon <gravity@mjcoon.plus.com> wrote:

In article <ba8aofl9hjuhilp5hqvipv3sfat1r6bh6p@4ax.com>,
jlarkin@highlandsniptechnology.com says...

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

Sort of like a Sesamoid bone?

Nice simile.

Danke,

--
Don, KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

 

[Jasen Betts]

On 2020-10-13, jlarkin@highlandsniptechnology.com <jlarkin@highlandsniptechnology.com> wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

meh... you\'re using a socket intended for edge-of-board access in the
middle of a board, in that location you should use socket with a
hinged door.

https://www.newark.com/multicomp/460de08c3/memory-card-connector-sd-8-position/dp/50P9130

--
Jasen.

 

[John Larkin]

On Wed, 14 Oct 2020 22:35:26 -0000 (UTC), Jasen Betts
<usenet@revmaps.no-ip.org> wrote:

On 2020-10-13, jlarkin@highlandsniptechnology.com <jlarkin@highlandsniptechnology.com> wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.


meh... you\'re using a socket intended for edge-of-board access in the
middle of a board, in that location you should use socket with a
hinged door.

https://www.newark.com/multicomp/460de08c3/memory-card-connector-sd-8-position/dp/50P9130

Too late now. We had that part in stock (and in our PCB layout
library) from another project, where the SD card entered a box through
a little slot on the side.

It\'s only a minor annoyance to use, and the 27 pF cap fixes that.

Users can upgrade software over Ethernet, but sometimes it\'s easier to
just mail them a new SD card. They can hand that to a tech and say \"go
plug this in.\"

 

[Simon S Aysdie]

On Monday, October 12, 2020 at 8:43:56 PM UTC-7, jla...@highlandsniptechnology.com wrote:

This SD card tends to catch in the socket on insertion, which is a
nuisance.

https://www.dropbox.com/s/klqg94qgsqdpj8o/SD_Cap.jpg?raw=1


Adding one 27 pF 0603 cap lifts it up a bit and fixes the problem.
It\'s on the schematic for the next rev.

It\'s cool, an unconnected capacitor floating in the middle of the
schematic sheet.

I did that many years back for Flex-into-Samtec connector. There were actually two to help get the height right for guiding into the connector.