peltier

could some one please recomend a suitable peltier for a moded toucam 2,
there seems to be a large range on rs components.

Thanks Rich D

"RICHARD DAVIES" wrote in message
...
could some one please recomend a suitable peltier for a moded toucam 2,
there seems to be a large range on rs components.

Thanks Rich D

Hi Rich,

It depends on the design you are proposing to use.
If you are going to lift the CCD and cool via a cold finger on the back of
the chip, then a small one with only a few watts and a passive heat sink
would be sufficient.
If you plan to cool indirectly, eg cooling the board and CCD chip via a lump
of metal bolted to the board in some way, I would go for one of 15-20W and a
fan cooled heatsink. You can see an example of an indirect cooling design on
my website (Not a Toucam though)
http://www.leadbeaterhome.fsnet.co.uk/1004xcam2.htm

It easier to provide power for ones operating around say 6-8v compared with
some which run at 1.5v You can see an example of an 8v 17w one which would
probably be suitable for indirect cooling running at around 6v 2.5A, and a
heatsink and fan here.
http://www.sciencestore.co.uk/StoreElectronics.htm
You may find them cheaper at surplus component sites compared with RS

The important things to watch for are good thermal contact from peltier to
CCD and heatsink, an efficient heatsink (It should run close to ambient
temperature -not warm to the touch. You also need to think about how to
avoid condenstion/frost on the CCD

Robin
----------------------------------------------------------------------------
-
Robin Leadbeater
54.75N 3.24W
http://www.leadbeaterhome.fsnet.co.uk/astro.htm
----------------------------------------------------------------------------
-

Robin Leadbeater wrote:

You may find them cheaper at surplus component sites compared with RS

You can buy direct and on-line from Marlow industries - RS and Farnell's
supplier.

Steve

Robin Leadbeater wrote:
The important things to watch for are good thermal contact from peltier to
CCD and heatsink,

This is absolutely critical. DO NOT USE EXCESSIVE amounts of thermal
transfer grease - lap the heatsinks flat on a glass plate before
assembly, smear with a barely translucent film of compound, then
assemble with sufficient pressure to clamp the device firmly. Make sure
the heatsinks are sufficiently thick to not deflect with your clamping
forces too.

We use Peltier Cells in the instruments I design and build, we cycle
the system attached to the cell from +40 to -40 roughly once every 10
minutes, and we have never, ever, had a device fail in the field, when
prepared as above - some units are 18 years old and in daily use still.

Steve

thanks for the advice!!

Rich D

I suppose this isn't suitable is it?.

Rich D

"Steve Taylor" wrote in message
...
Robin Leadbeater wrote:

You may find them cheaper at surplus component sites compared with RS

You can buy direct and on-line from Marlow industries - RS and Farnell's
supplier.

Steve

RICHARD DAVIES wrote:
I suppose this isn't suitable is it?.

Rich D

What ?
;-)

Steve

PS How's your 9" Dob ?

here it is
http://www.mainlinegroup.co.uk/mless...id_element=498
"Steve Taylor" wrote in message
...
RICHARD DAVIES wrote:
I suppose this isn't suitable is it?.

Rich D

What ?
;-)

Steve

PS How's your 9" Dob ?