F-16 pitot tube for RV - Page 2

tonyjohnson · #11 03-13-2005, 07:31 PM

For those of you who asked me to let you know what happened when I tested the pitot tube......I hooked it up to house current, using a dimmer switch set on the lowest setting. It heated up. I was afraid to turn up the power because the tube got too hot to hold with the lowest power setting available.

Next I will see how it responds to 12 volt input at a low setting.

Tony

Captain_John · #12 03-13-2005, 08:13 PM

Hmmm, very interesting!

One thing you will want to watch is amps!

Watts is a function of volts times amps. As your volts DECREASE your amps will INCREASE, so long as your resistance remains the same... and it will for the most part.

Too high a current (too many amps) has a possibility of toasting your pitot lead wires. Keep an eye out for that. Once the smoke leaves the unit, it is hard to get it all back in!

CJ

Captain_John · #13 03-13-2005, 08:20 PM

Incedentally, keep in mind that your ampacity will increase by approximately TENFOLD, as the difference in test voltages is 10 times (12vdc compared to 120vac).

Wattage is equal to volts times amps... or P=EI
Voltage is equal to amps times resistance... or E=IR

Hope this helps.

CJ

tonyjohnson · #14 03-13-2005, 08:26 PM

John,

Thanks for the info. My plan is to acquire an adjustable resistor, set it for the highest resistence, and run 12volt power through it into the tube. I will increase the resistence until I find the right amount to heat the tube up but not smoke it.

Do you have any suggestions about what resistance I should start with? Does that seem a workable plan?

Tony