Patent ID: 8123176

Claim:
A method for controlling a toy helicopter, the helicopter having a first rotor and a second rotor, the first rotor being driven by a first motor, and the second rotor being driven by a second motor, power being provided to the first motor and the second motor using pulse width modulation; the first rotor having a first rotor speed and the second rotor having a second rotor speed, the first rotor speed and the second rotor speed being adjusted such that the helicopter is stable in flight, a ratio of the adjusted first rotor speed to the adjusted second rotor speed defining a target ratio; the method comprising the steps of: (a) measuring a first rotor speed, measuring a second rotor speed and determining a ratio of the first rotor speed to the second rotor speed; (b) if the ratio is greater than the target ratio, performing at least one of decreasing the power to the first rotor by a fixed increment and increasing the power to the second rotor by a fixed increment; (c) if the ratio is less than the target ratio, performing at least one of increasing the power to the first rotor by a fixed increment and decreasing the power to the second rotor by a fixed increment; and (d) repeating steps (a) to (c) until the ratio and the target ratio are within a predetermined margin; wherein measuring the first rotor speed comprises measuring a feedback voltage of the first motor and measuring the second rotor speed comprises measuring a feedback voltage of the second motor.