| abstract |
An electric powered bicycle having a dip sensor or switch and/or a gradient sensor or switch. The bicycle comprises front and rear wheels each rotatably supported by its frame; a chain slung between said wheels and a chain set for transferring manual power to said wheels; an electric motor coupled to one of said wheels for driving said wheel directly; and a power supply capable of supplying electric power to said motor. The dip or gradient sensors are associated with a pulse width modulation circuit. |