TECs for sale - UK vendor

[stanwax]

Hi all
I have often searched on eblay for Peltier tec devices only to find most often the only ones around are 40 or 62 mm devices. These are fine for 'heavy duty' laser apps but I have been looking to buy some smaller ones that I can use in my DPSS projects.
At the weekend I came across this seller http://search.ebay.co.uk/_W0QQsassZmarthafecker
who has New Tecs available down to 15mm - I have no association with this seller other than I bought some 20 and 25 mm devices which arrived today - and they are very good.

DPSS project back on

Rob

[andy_con]

http://www.laser-man.co.uk/2006/inde...id=22&Itemid=6

i plucked this one on ebay about a year ago. its tiny but freezes in seconds

[stanwax]

Yep Andy I have bought little ones before but they are often too small or cant be got regularly - this looks like a decent supply of a good range of different sizes.

Rob

[dave]

Nice work. Ill be hitting this seller up shortly I think

[kaz]

nice find Rob ill be having a couple, never played around with these before.

[stanwax]

They are cool (no pun) useful if you are building your own DPSS or diode stuff and freak you out when you first play with one - its just not natural to put electrical power in and for it to get cold!

Have fun

Rob

[drlava]

interesting seller name.. !

[dave]

I just thought I would dig this thread up..

The ebay seller does not seem to have any small modules left - You guys must have bought them all

I found this guy tho, and so far his service has been great

http://www.thermoelectricsupplier.com/

They have a good range, and their prices aren't too expensive

[CDBEAM]

I am using (2) two 113 Watt TE units in my DPSS build project. They are 60mm x 60mm.
Just a note.....if when you first get your TE units....you hook them up...right away to see if these things really work.....Well.....here is what happens....
At first...the one side gets cold,cold.....and the other side gets really hot...so far....this is what I expected....then...after about 30 seconds operating.....the cold side starts to get less and less cold....while the hot side gets really hot !!! I then said "S,P,D,H"...what is going on ????? Have I burned them up ?????? did I get a defective unit ???? NO...and NO !!
I discovered that you must have the hot side attached to a heatsink....so as to remove the heat out and away from the junction....and that without using a heatsink.....the hot side heat radiation just heats up the whole unit....at least that is how it is with the units I have....but I assume ALL
Peltier Junctions are the same !!
Possible....most of you allready know this !!! I did not !! Just a little note for anyone unfamilar with TE units.

BoB / CDBEAM

[tocket]

That is how TEC works. The peltier element can only maintain a certain temperature difference between the two sides. As it operates the hot side will need to dissipate the full electrical effect (113W in your case if you run it at full effect) as well as whatever heat is being transferred from the cold side (typically around 50% of the electrical effect). If the cooling is inadequate the temperature of the hot side will rise and the cold side will follow. This is easy to understand when you consider that the peltier element has a thermal conductivity, though they are designed to minimize it as it counteracts the peltier effect. Do not run it too hot, or it will break (like most things)!

What kind of monster DPSS laser are you building anyway?