Most of my time is spent near London, Ontario (the other London) where the weather is, well, crap. During the summer months it can be decent with lots of clear (but short) nights but, in the winter, we can be blessed with weeks of overcast skies. And in between, the saddle seasons can be cool and damp. Prime time for the formation of dew on equipment. The observatories that I’ve been working on don’t have a lot of circulation and tend to feel very humid inside – even after outside humidity has dropped.
There are, of course, commercial dew controllers available but what I wanted was something that would switch both AC and DC equipment when the dome temperature was approaching the dew point. Vents with AC fans have been installed in the domes and smaller DC fans and heaters are strategically placed to try to keep the optics and CCD enclosure as dew-free as possible.
What you need…
First, keep in mind that I’m not an electrician. This is all done at your own risk…
- Arduino Uno or Mega
- 4 channel relay board
- BME280 temperature and humidity sensor
- jumpers
- a couple of electrical receptacles (I wanted 2 – 1 temperature controlled, 1 always live)
- an enclosure to hold everything
- AC Power cable (make sure to use one with a proper power rating)
- 12V power adapter (for Arduino and any 12V accessories like heaters or fans)
- heaters and fans
More to come…