Electric Flight

摘要

I find many modelers, even those who regularly fly electric, can't tell me what current their motor is drawing. Why is this important you ask? Well, current governs the size of the battery that you need, how efficiently you are running the motor, and even if you will burn it out. The size of the wire and connectors are also a function of the current drawn, as is the switch and/or timer capacity. It's pretty easy to determine the voltage—you count the number of cells and multiply by the volts per cell. Measuring voltage is also easy—you just place the leads of a voltmeter across the leads of the battery. Determining the current is not so easy. For a given voltage, the current drawn by a motor is a function of prop size or how the motor is loaded. It is entirely possible to load the motor beyond its peak power point and draw more current while producing less power out to the prop. This current is wasted as heat trying to burn out the motor. Measuring current requires breaking the circuit and inserting an ammeter in one of the wires going from the battery to the motor.