$4.80 Dew heater

[Lee]

After last night's dew, and my un-preparedness - action was needed. With some help from Alan's How-to article (http://www.iceinspace.com.au/index.php?id=63,292,0,0,1,0), built a dew heater for the ED80. Total materials cost $4.80 - one length of nichrome wire and two lengths of heat shrink. You get enough nichrome for two, so the next one will cost $2.....

Runs from 12V, draws 430mA (about 5W) - gets nice and warm. Testing tonight!

[Astro78]

Nice work. I got carried away, built the electronic controller (all day) and forgot the darn heaters. :screwy:

[iceman]

Let me know when you go into production :)

[Lee]

What function does the controller do? Temperature control???
I just included a 2A fuse in the circuit.....

[Glenhuon]

Havn't looked at the circuit, but should imagine its a variable voltage regulator (LM317T or similar). I used one for the speed control on the DSI fan and on a few other voltage reducers with the solar panels. One of mans great inventions :)

Bill

[Astro78]

The electronic controller besides looking really cool (cannot upload pics - any advice??) is a pulse width modulator, which allows for lowering the current with near perfect efficiency.

So really only advantage with batteries. Old style POT switches that still allow you to adjust the heat waste a heap of power, so better off either being on/off only - no adjuster.

Production: the thought did cross my mind. The one's from the states are expensive, really expensive.