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Name/source for mounting hardware

D

David Lesher

Jan 1, 1970
0
I'm seeking those clips that hold TO-92 cases. They look sorta
like the number 9, with the TO-92 going in the donut hole, and
the tail having a hole for a mounting screw. They hold the
device parallel to the mounting surface.

But I am having no luck finding the right term to describe such
to Mr. Digikey or Ms Mouser.....Suggestions?

I'm open to alternatives; our task is to fasten a temp sensor
to a 0.25" OD copper line to sense the fluid temp. within...
I planned to solder the clips to the line...
 
C

Cydrome Leader

Jan 1, 1970
0
In sci.electronics.design David Lesher said:
I'm seeking those clips that hold TO-92 cases. They look sorta
like the number 9, with the TO-92 going in the donut hole, and
the tail having a hole for a mounting screw. They hold the
device parallel to the mounting surface.

haven't seen those in a while.
But I am having no luck finding the right term to describe such
to Mr. Digikey or Ms Mouser.....Suggestions?

It's not quite what you want, but might work, and is probably the only
off the shelf item like this anybody even makes:

http://www.aavid.com/products/standard/92fg

here's how it mounts. Cut the top tab and legs off and just solder it to
the tube? It's going to look pretty homemade.

http://www.rapidonline.com/catalogueimages/module/M077178P01WL.jpg
I'm open to alternatives; our task is to fasten a temp sensor
to a 0.25" OD copper line to sense the fluid temp. within...
I planned to solder the clips to the line...

Tough one as you've got the worst possible shapes to join.
 
J

JB

Jan 1, 1970
0
David Lesher said:
I'm seeking those clips that hold TO-92 cases. They look sorta
like the number 9, with the TO-92 going in the donut hole, and
the tail having a hole for a mounting screw. They hold the
device parallel to the mounting surface.

But I am having no luck finding the right term to describe such
to Mr. Digikey or Ms Mouser.....Suggestions?

I'm open to alternatives; our task is to fasten a temp sensor
to a 0.25" OD copper line to sense the fluid temp. within...
I planned to solder the clips to the line...

--
Keystone do some interesting stamped metal parts.

regds.
JB
 
R

Rick

Jan 1, 1970
0
Jeff Liebermann said:
I found a few attached to transistors, but nothing sold individually.
Try your luck and see if you can do better:


Ummm... TO92 heat sink?


If that's part of a temperature control system, it's not going to work
very well. The problem is that you're measuring the temperature of a
big copper tubular heat sink. It will take a while for the fluid to
heat or cool the copper tubing resulting in a rather slow response
time. If there's any air flow over this thing, it will cool the temp
sensor and copper, resulting in what might be a substantial
temperature error. Basically, you want to measure the temperature of
the fluid and not the temperature of the tubing or the environment.

I suggest you drill a small hole in the copper tubing, shove in a
small glass thermistor probe that contacts the fluid and *NOT* the
copper tubing, and seal with epoxy glue.
<https://www.google.com/search?q=glass+thermistor+bead&tbm=isch>
You'll have much faster response, better accuracy, and less time
wasted trying to find strange heat sinks.

--
Jeff Liebermann [email protected]
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

If you insulate the sensor AND the pipe it will work. If the temperature is
not too high you can use something like "Great Stuff".
Rick
 
S

Spehro Pefhany

Jan 1, 1970
0
I suggest you drill a small hole in the copper tubing, shove in a
small glass thermistor probe that contacts the fluid and *NOT* the
copper tubing, and seal with epoxy glue.
<https://www.google.com/search?q=glass+thermistor+bead&tbm=isch>
You'll have much faster response, better accuracy, and less time
wasted trying to find strange heat sinks.

A more intrusive way is to adapt the 0.25" tube to a larger (maybe
3/8") tube with a T-fitting so the fluid makes a 90° turn, and insert
a sealed probe deep into the larger tubing (say 10 diameters of the
probe OD plus the sensitive end length). The hard right turn also
causes turbulence if you have enough flow, and prevents laminar flow
which will screw up your readings. Read about Reynolds numbers and
such if you're interested- it can be important. A 1/8" OD probe would
be better than something a TO-92 will fit into.

More Mickey Mouse (tm) would be to put a dollop of heatsink compount
on the TO-92 (with attached and electrically insulated leads,
obviously), wrap wide adhesive copper tape around the two, and finish
with some adhesive-lined shrink tubing and outer (thermal) insulation.
 
S

Spehro Pefhany

Jan 1, 1970
0
To get serious, solder a thermocouple to the copper pipe.

And sandwich that (short) section of copper pipe between sections of
plastic pipe.
 
J

Joerg

Jan 1, 1970
0
David said:
I'm seeking those clips that hold TO-92 cases. They look sorta
like the number 9, with the TO-92 going in the donut hole, and
the tail having a hole for a mounting screw. They hold the
device parallel to the mounting surface.

But I am having no luck finding the right term to describe such
to Mr. Digikey or Ms Mouser.....Suggestions?

I'm open to alternatives; our task is to fasten a temp sensor
to a 0.25" OD copper line to sense the fluid temp. within...
I planned to solder the clips to the line...

I believe they are called "transistor clips". Talk to these guys:

http://www.atlee.com/TransistorClips.asp

Careful with beryllium-copper, personally I would not use those.
 
M

Martin Riddle

Jan 1, 1970
0
I'm seeking those clips that hold TO-92 cases. They look sorta
like the number 9, with the TO-92 going in the donut hole, and
the tail having a hole for a mounting screw. They hold the
device parallel to the mounting surface.

But I am having no luck finding the right term to describe such
to Mr. Digikey or Ms Mouser.....Suggestions?

I'm open to alternatives; our task is to fasten a temp sensor
to a 0.25" OD copper line to sense the fluid temp. within...
I planned to solder the clips to the line...

Thats called a 'loop strap'
http://www.mcmaster.com/#loop-straps/=mjaljx

You can try Keystone, RAF too.

Cheers
 
J

Joerg

Jan 1, 1970
0
Spehro said:
How about beryllium-copper with cadmium plating?

Probably ok as long as nobody saws or scrapes. But then one fine day
somebody does ...
 
S

Spehro Pefhany

Jan 1, 1970
0

I'm imagining the copper tube goes through bulkhead fittings, into
tanks, bolted into pumps, held with hangers mounted to metal etc. that
could significantly change the temperature of the tubing relative to
the liquid flowing inside.

If your model is an effectively infinite length of thermally isolated
copper tube with liquid of the same temperature throughout then there
is no need of the insulation I suggested.
 
J

Jamie

Jan 1, 1970
0
David said:
I'm seeking those clips that hold TO-92 cases. They look sorta
like the number 9, with the TO-92 going in the donut hole, and
the tail having a hole for a mounting screw. They hold the
device parallel to the mounting surface.

But I am having no luck finding the right term to describe such
to Mr. Digikey or Ms Mouser.....Suggestions?

I'm open to alternatives; our task is to fasten a temp sensor
to a 0.25" OD copper line to sense the fluid temp. within...
I planned to solder the clips to the line...
What you need then, is to use those circuit board fuse holders..

you get the size for the 1/4" fuses and you can snap the sensor in the
holder. You can solder this to a copper piece of course.

The URL links are far to long but go to mouser and look for
"Fuse clips" you put two of these on your pipe so that the wires
will hang out on one end and the tip of your sensor will sit in the
other end.


Jamie
 
C

Cydrome Leader

Jan 1, 1970
0
In sci.electronics.design Spehro Pefhany said:
How about beryllium-copper with cadmium plating?

You forgot the beryllia insulating (electrical) wafer that's ground into a
special shape.
 
D

David Lesher

Jan 1, 1970
0
Moving fluids, especially water, have enormous equivalent thermal
conductivities, and copper is pretty good, too. Air is a terrible thermal
conductor. So the surface temp of a copper tube that carries a flowing liquid is
very close to the liquid temp. The time constants will be very fast.
Add a little external insulation to do even better.

Exactly our plan. We will not create leak opportunities,
there are enough already. If we wrap the tube+sensor
with insulation, it will be fast enough for our needs.
 
D

David Lesher

Jan 1, 1970
0
The fuse clips idea is a good one; we'll look at that.

The sensor will be on a 1-2" long segment of tubing solely
for temperature sensing. The plastic tubing isolates it.
It will be wrapped with insulation against wind.

Yes, it won't be the fastest response, but in this application,
BFD; it will be fine.

We are NOT going to play with thermistors, thermocouples and
other instruments of aggravation and annoyance; I'm in recovery
from same. The Device Gods let us buy I2C and 1-Wire sensors,
and the output is bits.... nice friendly bits.

The 1-Wire vs. I2C decison is more nuanced; I2C has a TO-220
package but the tab is not electrically isolated. 1-Wire has
TO-92's that we can bury in a hole on the busbars. The CPU has
I2C support directly; but there's a I2C to 1-Wire chip that
sounds interesting, the DS2483. Maxim wants $85 for their simple
eval kit - DS2483K# so we'd make our own from a 2483.
 
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