Specifications

40 AUTOSTAR CCD PHOTOMETRY
This cooling modification can be used on all the DSI series
cameras. In addition to reducing dark current, electronic cooling
increases the camera's sensitivity.
TEC Cooler Mods
Perhaps the most effective way to cool the CCD is by using a
Peltier Junction Thermoelectric Cooler (TEC). Peltier Junction
TECs are fascinating devices. They consist of a sandwich of
semiconductors connected in parallel, between two metallic plates.
By applying a DC voltage across the device, one plate gets hot
while the other one is cooled. The amount of heat and cooling
produced can actually be surprising! Care must be taken when
experimenting so that the unit doesn’t overheat. Attaching a finned
heatsink and a fan is very important on the hot side. Thermal
grease needs to be applied on both plate surfaces to provide
effective transfer of the heat (and cooling).
Some will note that there is no temperature regulation or sensor
included in our mod. These features could be added, but would
increase the complexity. The lack of temperature regulation has
not been a problem at HPO. If the camera is allowed to run with
power and cooling ON for 15 to 30 minutes, the temperature will
stabilize. The exact temperature is not important. Once the unit has
stabilized, new dark frames for that evening should be taken. This
procedure works well.
Note: The modifications described here involve opening the
camera case to install the equipment, and probably will void the
camera warranty. Some experience with electronics or kit
building is highly recommended. A bolt-on TEC cooler backplate
assembly is available commercially. A simple clip-on 12VDC
electric fan is also available as a standard accessory from Meade,
which will lower the camera temperature about 9°F (5°C).