power generation from door opening

[ijasti]

A method and an apparatus for generating electricity from the ordinarily wasted mechanical energy expended when opening a door. The apparatus includes a ratchet attached to a door which rotates a connecting shaft when the door is opened. The connecting shaft is connected by a gear train to a spring housing in which a spiral shaped spring is fitted and connected to a spring shaft. The spring shaft is coupled by a second gear train to the driveshaft of a generator. Opening the door causes compression of the spiral plate spring, which causes rotation of the driveshaft of the generator in order to generate electricity when the spring is uncoiled. A stopper engages teeth on the bottom plate of the spring housing to prevent reverse rotation of the spring shaft when the door is closed.