2018-12-27, 11:52 PM
(2018-12-27, 02:15 PM)abarrow Wrote: That's a good question! I looked it up - one of the production units I've been looking at is solar powered (https://calypsoinstruments.com/shop/prod...emometer-7), and they claim it will operate a very long time with no sunlight after a charge. As for the unit I was looking at on EBay, the manual says they require "10-15VDC at 29mA RMS".
Pretty darned good!
What is a "very long time" ? In winter you might only get 6 hours daylight. Overcast the solar output is 20% if you are lucky. So at 29mA you are going to need a 6 watt solar panel up there to ensure it can operate all the time. How big is the solar panel?
I just tested today for the first time wind speed/direction sensors I printed on my 3d printer. It took me about 6 hours to print. This is really great because if something breaks off when you hit a tree, you can print that part again or you can print it larger to make it more sensitive.
It uses a magnet to measure wind angle, so very low friction, but I want to replace the stainless bearings with ceramic.
The cups have a magnet that fits in the printed hub to trigger a magnetic reed switch which is a proven method, and I see no real reason to change it.