After a dewy FallNStars star party weekend it was time to go back and start working on making work all of the various dew heating bits and pieces we have laying around.
I found a bag of heaters, and a mouse nest. Got rid of the mouse nest and discovered a hole in the middle of the 40″ heater, mainly the felt
cover with a few nibbles on the heater as well. And on another 6″ heater, the end velcro strap was totally gone.
So.. All of these items are now stored inside a plastic bin. Yes, I know this will not stop the mouse built it will slow him down.. and I will be
able to see inside and if I see him, wave a goodbye! Will repair these two in the next few days.
So, a kendrick 40″ strap will work on a 12″ diameter telescope (C=D*Pi) D=C/Pi=40/3.14 = 12.7″
The 19″ strap (19/3.14=6) is good for a 6″ diameter telescope and the 6″ is good (6/3.14=1.9) for a 1.25″ eyepiece.
Resistance wise, the 6″=52 ohms, the 19″ is 9.4 ohms and the 40″ is 5.2 ohms
V=IR, Power=IV= V^2/R so
the 6″ strap at 52 ohms at 12 vdc gives 12^2/52=144/52= 2.77 watts
the 19″ strap at 9.4 ohms at 12vdc gives 12^2/9.4=144/9.4= 15.3 watts
the 40″ strap at 5.2 ohms at 12vdc gives 12^2/5.2=144/5.2 = 27.7 watts