August 15, 2008

What is a formula to find horsepower on a rc airplane?

A lot of rc airplane gives me, Kv (RPM/V), weight, Resistance (Ri), Idle Current (Io) and some gives me the prop range

Voltage is a unit of electromotive force. Resistance is what controls the current at a given voltage. The problem you have in making such a conversion is that you do not have enough data. Horsepower is a unit of work. You would need to assign a value to the RPM question.

Calculate by using Ohm's law. current = voltage/resistance. Your voltage is a function of RPM speed and you said you have the value for resistance. Next, you need to convert this to a unit of work, in this case Watts. Again using Ohm's law calculate watts = current X voltage.

You need to know that 746 watts = 1 hp. Watts/746=hp

Not all that difficult, just takes 3 steps to solve. Good luck.

Filed under RC by Ray

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Comments on What is a formula to find horsepower on a rc airplane? »

October 31, 2007

some-yank @ 4:16 am

Voltage is a unit of electromotive force. Resistance is what controls the current at a given voltage. The problem you have in making such a conversion is that you do not have enough data. Horsepower is a unit of work. You would need to assign a value to the RPM question.

Calculate by using Ohm's law. current = voltage/resistance. Your voltage is a function of RPM speed and you said you have the value for resistance. Next, you need to convert this to a unit of work, in this case Watts. Again using Ohm's law calculate watts = current X voltage.

You need to know that 746 watts = 1 hp. Watts/746=hp

Not all that difficult, just takes 3 steps to solve. Good luck.
References :

garrisonbight @ 5:54 am

One HORSEPOWER in electrical terms is 780 WATTS… do your own math to figure out what percentage of 780 watts your R/C plane develops
References :

Airmech @ 11:59 am

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