Electronic device and controlling method thereof

摘要

The present invention seeks to provide an electronic device in which a braking torque can be increased while reduction in power generation is suppressed, and in which a rotor is prevented from stopping or rotating at an excessive speed. An electronic device includes a generator 20 which is driven by an mechanical energy source and a rotation controller 50 which controls the rotational period of the generator 20. The rotation controller 50 includes switches 21 and 22 which connect both ends of the generator 20 in the form of a closed loop, a chopping signal generator 150 which generates a chopping signal applied to the switches, and a brake control circuit 55 which performs chopper control of the generator by switching over three brake control modes including a high-power brake control in which an effective braking force generated by applying the chopping signal is large, a mid-power brake control, and a low-power brake control in which the effective force is small. <IMAGE>