Quote:
Originally Posted by ZeroID
6 volts will not make a big difference to temp reduction I suspect. 5 v only got me 8* although if I fix the conduction issue it might do better. 12 v was pulling about 4.5 amps so you are going to need some more power capacity. I'm lucky, I have 240 vac to the OB so it is just a power supply connection.
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Thanks for the explanation on the heat-sink set-up - I assumed that your heat sink needed a circulating (pumped) fluid flow in order to be able to shift the heat load from the hot face to the fins.
I suspect the operating voltage WILL make a big difference on the lowest temperature I can reach at the sensor, but I'm hoping that 6 volts will get it "low enough", especially with a bit of insulation etc.
At 6 volts, my TEC can supposedly pump "up to" about 30 watts of thermal load at ambient temperature, before ultimately reaching a Delta-T of "up to" 40 deg C.
At 12 volts, it should be able to shift about 55 watts of thermal load at ambient temperature, before reaching an ultimate Delta-T of "up to" 70 deg C.
The time to reach thermal equilibrium will depend on how many amps you push through the TEC (more volts = more amps), and how good the thermal insulation is. In a perfect world, you only want to cool the sensor, but with this set-up, you have to cool the whole camera body, and deal with the "parasitic" heat load as well.
What temperature I actually see at the sensor will depend not only on how many volts / amps I am running, but it will also depend on my thermal efficiency (e.g. conductivity between interfaces, and "parasitic" thermal load, such as trying to cool the whole focuser assembly), and especially, the ability of the heat sink to keep the hot side of the TEC down to no more than about 50 deg C, say.