Scott Edward Garrett

US Patent:

56400713, Jun 17, 1997

Filed:

Oct 10, 1995

Appl. No.:

8/544420

Inventors:

Francis P. Malaspina - Gainesville GA
Simon Thomas - Lawrenceville GA
Sathya S. Prasad - Duluth GA
Scott M. Garrett - Lawrenceville GA

International Classification:

H02J 904

US Classification:

318139

Abstract:

In a circuit having an electromechanical transducer, such as a motor (22), a control switch (24) is controlled by a control circuit (26) to connect the motor to, and disconnect from, a battery (12). When control switch opens, thereby disconnecting the motor from the battery, the momentum achieved by the motor tends keep the motor turning, causing the motor to behave like a generator. A switch network (28) connects a first capacitor (30), which is initially discharged, across the motor at the same time the control switch disconnects it from the battery. The momentum of the motor, and any attached mechanical system (32), generates a transient charge which is collected by the first capacitor. When the voltage produced by the collected charge reaches a peak, the switch network disconnects the first capacitor from the motor, reorients the first capacitor, and waits to apply the voltage to the motor. A charge pump connected between the first capacitor and the battery may be activated to transfer the collected charge back to the battery if the motor is not to be started for some time.