Sunday, July 01, 2007

Making the Peltier cooling box for DMK

Below is the first version, I bought a $2 HKD plastic box for shielding. The reason why I used a plastic box is that, cooling will cause condensation, so I place everything inside a plastic box to keep the camera from moisture. Dessicant should be placed inside the plastic box to ensure the air inside is dry.

To fix the wiring. Originally, I planned to use a single 12V power source, and to connect the 12V fan and the Peltier module in parallel, since my heat sink and the fan is pretty small, my preliminary test shows that the Peltier module cannot be operated at 12V or else the heat sink will be overwhelmed. So, my thought is to add a variable resistor to cut down the voltage applied to the Peltier.

However, I failed badly, since at any setting of the variable resistor, the Peltier nearly didn't cool down, but when it's set at near zero, I could see the resistor actually light up with some bad smell. Obviously this simple design does not work at all.

So, to make thing simple, I removed the variable resistor and replaced it with another power socket so that I can apply 12V for the fan and a lower voltage for the Peltier.

I used 6V for the Peltier and the fan/heat sink is more than enough to drive away the heat, and I believe 8-10V can be used and I shall test again later. Maybe a 8AA rechargeable battery box is a good match at 9.6V, let's see.

At 6V, the Peltier module will not make the camera very cool, it's simply cool to touch, but no condensation even the plastic box does not have any dessicant inside. I believe it's 5-10 degree below ambient.

Here's the list of components:

1. Peltier module
2. A CPU or motherboard chipset heat sink with matching fan, the heat sink should be larger than your Peltier module
3. Power socket(s) (optional)


Macaron said...

I'm insterested in making simple use of the Peltier Module.
So what were the characteristics of your module?
Will it work if i use the current produced by a Dynamo ?(approx 0.5A, for 6V)

Oldfield So said...

thank you for your interest, but this is a long ago project so I lost the detail.

Macaron said...

I see ^^ sorry bothering you then and thank you anyway.
I think it might work i'm gonna try it soon.