i remmeber reading somewhere that the 2 side of peltier should be kept clean, no paste recommended. then again, different people have different results.
abit amazed by how u mention 72 watts as modest. the ccd draws it's power from the usb, which at max should draw something like 350ma@5v. that's less than 2 watt of heat produced. what voltage are u powering that tec? 12v? i would assume the temp at the cold side should almost reach 50c lesser than the hot side. lower than freezing point eh?
the starshoot II only runs the tec at 3v, and i assume it's merely a 30-40watt tec since it runs on 2 D sized battery, so best case only abt 6-7watt worth of cooling. 72watts is modest???
~MooEy~
First Light - DSI III Pro
I've worked with many peltiers and the lapping of heatspreaders / heatplates, but for PC applications.
Usually you do not want to apply the peltier directly to the surface to be cooled. Using a thin copper plate as a heatspreader will increase the efficacy of the peltier.
I normally use Arctic Cooling MX-2 or Arctic Silver 5 as the Thermal interface material normally, but AS5 requiring a curing time of about 200 hours during which the heat is cycled before it reaches its prime.
I've tried the Shin-Etsu compounds and the Liquid Metal (Gallium based) TIMs from CoolLaboratories also but they are harder to find and offer similar performance.
A 72W peltier should definitely lower the CCD to sub-zero temperatures, I think its not drawing the full 72W off the USB power, it its only dropping to 25C below ambient.
I always use thermal interface material, and for insulation I usually use expanding foam and/or neoprene sheets. Condensation is really a killer in our climate, especially when to turn the system off.
I usually only lap copper surfaces. Starting with 800 grit sandpaper, onto 1000 grit and finishing with 1200 grit. Its a lot of work for that additional 1 - 2C where PC CPUs is concerned though.
Usually you do not want to apply the peltier directly to the surface to be cooled. Using a thin copper plate as a heatspreader will increase the efficacy of the peltier.
I normally use Arctic Cooling MX-2 or Arctic Silver 5 as the Thermal interface material normally, but AS5 requiring a curing time of about 200 hours during which the heat is cycled before it reaches its prime.
I've tried the Shin-Etsu compounds and the Liquid Metal (Gallium based) TIMs from CoolLaboratories also but they are harder to find and offer similar performance.
A 72W peltier should definitely lower the CCD to sub-zero temperatures, I think its not drawing the full 72W off the USB power, it its only dropping to 25C below ambient.
I always use thermal interface material, and for insulation I usually use expanding foam and/or neoprene sheets. Condensation is really a killer in our climate, especially when to turn the system off.
I usually only lap copper surfaces. Starting with 800 grit sandpaper, onto 1000 grit and finishing with 1200 grit. Its a lot of work for that additional 1 - 2C where PC CPUs is concerned though.