Thanks Peter for the feedback, much appreciated!
Quote:
Originally Posted by peter_4059
how are you measuring the temperature? I'm using one of the Aus Geographic inside/outside temp and humidity sensing devices - it has an external sensor for outside temp that I'm attaching to the end of the cold finger.
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I'm using my Fluke DMM with JK thermocouple.
It agrees pretty well with the same inside/out thermometer you describe.
The DMM has a faster reaout sample rate though for fine readings.
In the pic attached I have shown where the thermistors are connected.
It's the coldest part of the block.
Quote:
Originally Posted by peter_4059
have you got it attached to the DSI and if so have you noticed any noise issues? Also have you sealed up the DSI case/provided dessicant to prevent dew condensing on the electronics?
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Not yet. Once I get this thing cycling nice and not too much
of a variance...as long as I can set any temp around 5-10C that
would be fine for summer imaging.
No need to go much lower because the 429 CCD is so clean a picture
anyway at below 20!
No thoughts yet on sealing it. As I said in an earlier post, the layout
and the neoprene grommet at the front lends itself well to volume
filling/ insulating etc.
Quote:
Originally Posted by peter_4059
I had another thought - I've embeded the temperature sensing device for the control circuit in a big chunk of aluminium that sits between the peltier and the flattened back of the DSI. Perhaps this thermal mass is helping to hold the temperature more constant. The peltier, fan and the mounting was from a cheap in-car mini fridge.
Peter
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I think you might be right here Pete.
In the next day or so I'll try feeding the pelt with a PWM 6-12V and
see if I can get a nice cyclic minimum delta.
cheers,
Steve