Peltier plate TES1-11930 with hole for cold stage

pennine56 · Post by **pennine56** » Thu Apr 12, 2018 5:51 am

Hi

Peltier plates with holes seem much less common than the solid plates but the TES1-11930 3 x 3 cm with 5 mm hole 14V / 3A 24W works well for transmitted studies from early trials. (Plate mis-labelled as TES1-11903 by some eBay and Alibaba sellers.)

Easier to work with than the cheap TEC1-12706 solid plates which at 72W was struggling to lose the heat from the hot side.

Work so well that condensation which occurs below the dewpoint and needs to be controlled with a dry box around objective turned out to be an interesting subject. The droplets grow, coalesce and if freeze at this point by increasing Peltier current get attractive patterns.

Sequence below with Zeiss 6.3X planachro, quarter blue / green Rheinberg with LED ring on scope base (60 mm diam. 12 LED for car headlights) no condenser as reported by Dr Kevin Webb. Plate at 1A of rated 3A freezes water.

Setup not very elegant but the beefy heatsink gives good efficiency for temps at zero Celsius and lower. Fan overkill for flash cooling but no vibration on a solid Zeiss Photomic' with low power objectives used. Smaller heatsinks with fans tried to date not efficient enough at heat removal.

David

pennine56 · Post by **pennine56** » Tue Apr 17, 2018 12:17 pm

Maybe I'm easily pleased, but watching something akin to snowflakes growing (actually dew condensing and freezing) in real time in a warm room is rather fun and fascinating. Zeiss 2.5X objective, side gooseneck lighting.

This uses the Peltier plate at 10V 2A remarked on previously. Although as it's top lighting it doesn't need a plate with a hole so the very cheap TEC1-12706 would be fine.

ChrisR · Post by **ChrisR** » Tue Apr 17, 2018 6:34 pm

Interesting

. Any reason why you couldn't drill a hole in a cheaper unit?

pennine56 · Post by **pennine56** » Wed Apr 18, 2018 7:38 am

ChrisR wrote:Interesting . Any reason why you couldn't drill a hole in a cheaper unit?

Hi Chris

The plates as far as can gather from online resources are an array of semiconductors filling the whole plate area so would compromise the unit if drilled a hole.

These examples also have very tough ceramic plate tops.

The incident work including the water freezing doesn't need the annular plate, the much cheaper solid plates work well.

regards
David

mawyatt · Post by **mawyatt** » Wed Apr 18, 2018 7:56 am

Cool ideal

Now if I could just cool my camera down to say 3~4 Kelvin

Best,