Re: Homemade dew zappers.
Bob Bond (rgb@db1.ncube.com)
Fri, 31 Mar 95 10:17:33 PST
I figured 15 watts for the front of my 90mm refractor. I got that
number by looking at catalogs and talking to other ATMs. Since the
speed that it cools will depend on the outside air and the humidity, I
designed a controller that gives me a variable duty cycle. I supply
the full 12 volts during the on-cycle. Cycles are 20ms in length, with
the voltage on 0% to 100% of each cycle. I hooked up a red LED to the
circuit so that the controller doubles as a warning light for star
parties and so I get visual feedback as to the current duty cycle.
The controller has 4 RCA jacks so I can hook up 4 elements.