I should have thought of looking there, thanks.

Very strange specs. It says that you need more current on the higher
voltage system, which is wrong. You actually need less than half the
current on the double voltage system to produce the same amount of
heat. So for those pitot tubes it says you need 120W of heat for a
12V airplane and 360W of heat on a 24V airplane. I figure both
airplanes will ice the same regardless of the battery inside.

On the same page there is a pitot heater that needs 3-4 amps at 24V
(90W), so something is fishy here. The 3-4 amp is pretty doable with
a boost converter, the higher current (15 amps) stuff gets a little
fancier.

One idea I'd suggest considering is just running the 24V heater on
your 12V system. Realize that you're only putting 1/4 the heat into
the tube and fly accordingly into icing conditions. Don't fly as
high, as fast, or for as long in ice clouds. Its better than a non
heated tube and you've got a ready to go solution. Later, if you have
time and money, you can add the power supply to give full heat. There
seems to be some variabity anyway on how much heat a pitot tube really
needs to have, compare the 90W vs 360W above which is 1/4.

Regards

(B2431) wrote in message ...
From: (Jay)


How much power does a typical pitot tube heater need?


Aircraft Spruce shows 10 amps for 12 V and 15 amps for 24 V.

Dan, U.S. Air Force, retired