John Donald Cochoy

US Patent:

6686719, Feb 3, 2004

Filed:

Oct 1, 2002

Appl. No.:

10/262224

Inventors:

John Cochoy - Evans GA
Carlton W. Hearn - Augusta GA

Assignee:

Textron Inc. - Providence RI

International Classification:

H02P 742

US Classification:

318801, 318139, 318254, 318800, 318812, 318813, 180 65, 180 656, 180 658

Abstract:

A control system for an electric vehicle, such as a golf car, that includes a plurality of power MOSFETs. The vehicle includes a shunt wound motor including an armature coil and a field coil. One of the MOSFETs is connected in parallel across the armature coil and another MOSFET is connected in series with the armature coil. The MOSFET across the armature coil includes a freewheel diode. When the motor is operating below its base speed, i. e. , when the back EMF is below the power supply voltage, a current flow can be induced by momentarily turning on the series MOSFET, shorting the armature coil. Because of the residual inductance in the motor, a current flow in the counter clockwise direction is initiated at which point the series MOSFET is turned off. Consequently, a large voltage spike across the motor occurs which results in current flow back into the battery pack. By quickly turning the series MOSFET on and off the current flow can be maintained, and the regenerative braking can occur even at slow speeds.

US Patent:

20010043049, Nov 22, 2001

Filed:

Dec 14, 2000

Appl. No.:

09/736657

Inventors:

John Cochoy - Evans GA, US
Carlton Hearn - Augusta GA, US

International Classification:

H02P005/34
H02P007/42

US Classification:

318/801000

Abstract:

A control system for an electric vehicle, such as a golf car, that includes a plurality of power MOSFETs. The vehicle includes a shunt wound motor including an armature coil and a field coil. One of the MOSFETs is connected in parallel across the armature coil and another MOSFET is connected in series with the armature coil. The MOSFET across the armature coil includes a freewheel diode. When the motor is operating below its base speed, i.e., when the back EMF is below the power supply voltage, a current flow can be induced by momentarily turning on the series MOSFET, shorting the armature coil. Because of the residual inductance in the motor, a current flow in the counter clockwise direction is initiated at which point the series MOSFET is turned off. Consequently, a large voltage spike across the motor occurs which results in current flow back into the battery pack. By quickly turning the series MOSFET on and off the current flow can be maintained, and the regenerative braking can occur even at slow speeds. The control system also allows the vehicle to be operated at speeds below its base speed, and provide field current control by measuring the armature current in the negative quadrant of the field map.

US Patent:

20130300430, Nov 14, 2013

Filed:

May 9, 2012

Appl. No.:

13/467834

Inventors:

Ryan LINDSAY - Brentwood CA, US
Roger WHITE - Livermore CA, US
Scott BOWMAN - Fairfax CA, US
John COCHOY - Brentwood CA, US

Assignee:

CURTIS INSTRUMENTS, INC. - Livermore CA

International Classification:

G01R 31/08

US Classification:

324522

Abstract:

An isolation monitor is disclosed in which a switchable bias voltage is imposed on a chassis ground. An isolation voltage is measured when a bias voltage is applied. When there are no electrical faults, the isolation voltage swings up and down to known values. When a fault occurs, the isolation voltage will not to swing to the known values, and thus the isolation resistance can be measured and alarm generated if the isolation resistance falls below a threshold value.