MECHANICAL ASSEMBLY
This part of the document describes the Audine mechanical assembly. The camera includes 3 essential mechanical parts (See diagrams):
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Front side composing the interface with the telescope. This side incorporates the closure optical window.
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A 80-mm square body.
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A back side including the heat dissipator evacuating the system's calories and holding a fan as well as connectors.
Main mechanical parts of the Audine camera.
First step: position the optical window with glue on the front side. The optical window should be 50 millimeters in diameter and 3 millimeters thick. Spread a thin layer of glue (ideally silicon glue) on the surface in contact with the window on the front
Allow about 12 hours for drying.
Glue is spread over the entire surface. Do not apply too much glue or it will run onto the optical window.
Second step: install the Peltier module on the back. In the area outlined on the inside of the dissipator by the six threaded holes, spread the heat paste (a silicon grease loaded with a heat-conducting material). Spread the paste evenly with your finger
To ensure good thermal contact between the components, spread heat grease on the sides in mechanical contact with the Peltier module. Spread a thin layer of grease on both sides of the Peltier module. Applying huge amounts of grease is not nece
Installing the Peltier: the Peltier is positioned between the 6 threaded holes
on the back. The side to be stuck on the back is the one with the two soldered
wires (the hot side). Warning: do not put them the
wrong way!
Assembling the thermal drain: the drain has to be completely pressed up against the entire surface in contact with the Peltier module to ensure maximum effectiveness of the cooling system. To do so, screw in the 6 nylon screws rather tightly and homog
The 6 nylon screws are in place. Note the direction in which the module's 2 power supply wires are running with respect to openings on the back. This direction needs to be maintained to make the assembly of the camera easier. Note the four 25-m
Electrical connection of the Peltier: solder the wires of the Peltier module in
the holes provided for this purpose on the lower card. The solders should
be done on the component side. Be extremely careful
not to pull on the wires of the Peltier module, as the solders that are attaching
them are very fragile. It is almost impossible to re-solder a Peltier module
wire if the solders breaks.
Layout diagram showing the solders contacts of the Peltier module wires
(seen from component side). The contacts are twined together. The red Peltier
wire has to be soldered into one of the holes marked Peltier + and the black
wire into one of th
Peltier module wires are soldered on the CMS side. Pay attention to
the polarity.
Optical window heating option: if the CCD is at very low temperature, the convection of air inside the camera tends to cool the optical window, possibly causing condensation to appear on the outer side of the window. Very slight heating of the front side
If the resistance has a value of 10 Ohms, the power dissipated through the front is: P=U*U/R=25/10=2.5W, which makes it possible to raise the temperature of the optical window by 1 to 2 degrees, enough to prevent any risk of condensation.
The power resistance connected to the lower card parallel to the supply
of the Peltier module. The wires are soldered on the component side, contrary
to those of the Peltier module. The direction of polarization does not
matter here. On the resis
Fan: a 12V model is required, normally used for cooling Pentium microprocessors (50 x 50 mm size). With a drill, enlarge the attachment holes, located on the four corners of the fan, to a diamter of 5 mm. Then thread the two power wires through the 3-mm d
The wires need to be relatively short, but long enough for being able to handle the lower card and the fan. If they are too long, final assembly will be hindered.
The fan wires cross the back through a small hole.
Close-up of the fan wire assembly (assembly on CMS side). Refer to the layout
diagram: the fan's red wire must be soldered into the hole marked Fan
+ and the black wire (or combined red/black wire as in the case of the
photo) into the hole marked Fan - .