Cooling mod for the Watec WAT-120N Version 20. October 2005
Martin Elsässer

After having learned the positive effects of simple cooling measures i have made some attempts to develop a modification to the watec camera housing that provides for forced air cooling through a small fan.
Here are some images of my first attempt.

The modified camera housing

The standard camera covers were replaced with two pieces of aluminium, to which a 40mm standard fan was attached. The front-plate of the camera was modified, so that air could flow through the small chamber, which contains the ccd-chip. The fan blows the air from the top of the case across all circuit boards. As there is only a very small gap between the front plate of the camera housing and the ccd-chip-housing, i dont expect stray light to be much of a problem.
The modified camera, with fan on top, from behind. The gaps between fan and original back-plate need to be closed, so that all air is forced through the housing.
A small hole had to be machined into the left camera cover, to accomodate the (useless) connector for the iris-controlled lens. Might the connector simply be soldered out?
From the front, the circuit board of the ccd-chip is visible, as some of the frontplate has been removed, to allow air to flow.
Another image.
From above, through the operating fan, all the circuit boards and the ccd-chip (as the rightmost chip) can be seen. There is a very small gap between ccd-chip-front and the backside of the camera front-plate. Where there is light, air can flow, too.
From below, no cover has been installed yet. Some kind of protection will be required. The machined opening in the frontplate, through which the air can flow across the ccd-chip, can be seen at the right of the housing.

Effects of this mod

A dark image of the unmodified camera at room temperature, no airflow, maximum gamma settings to show the hot-pixels at their worst.
The dark image of the modified, cooled camera shows the positive effect very well: All the weaker hot-pixels have disappeared.

I have a more simplified and sturdier version of this mod in mind using 50x50x5 Aluminium profile, which would also be easier to build. Of course, a final version would also be painted/anodized black and should be better looking.