Start-up system for inverter driven motor including inverter bypass circuitry

Claim 2

A start-up system for an electrical motor connected to drive a mechanical load, comprising an AC generator connected to be driven from an input shaft which varies in speed, switching means having a set of movable contacts coupled to the motor, and having first and second sets of fixed contacts, a rectifier circuit coupled to the AC generator for providing a DC voltage, means for coupling at least some of the fixed contacts in the first set to the AC generator, an inverter connected for energization from the rectifier, which inverter has an output circuit coupled to at least some fixed contacts in the second set so that the motor can be initially energized over the first fixed contact set from the AC generator as the system is started, and thereafter energized over the second fixed contact set to supply the motor from the inverter.

Claim 3

An automotive air conditioning system comprising an alternator and a compressor connected to be driven from a motor, including switching means having a set of movable contacts coupled to the motor, and first and second sets of fixed contacts, a rectifier circuit coupled to the output side of the alternator, means for coupling at least some of the first set of fixed contacts to the output side of the alternator, an inverter having its input circuit connected for energization from the output side of the rectifier, which inverter has its output circuit coupled to at least some of the second set of fixed contactS, so that the motor can be initially energized from the output side of the alternator when the system is started, and thereafter the movable contacts can be displaced to engage the second set of fixed contacts and supply the motor from the inverter output voltage.

Claim 4

An automotive air conditioning system comprising an alternator and a compressor connected to be driven from a motor, including switching means having a set of movable contacts coupled to the motor, and first and second sets of fixed contacts, a rectifier circuit coupled to the output side of the alternator, means for coupling at least some of the first set of fixed contacts to the output side of the alternator, an inverter having its input circuit connected for energization from the output side of the rectifier, which inverter has its output circuit coupled to at least some of the second set of fixed contactS, so that the motor can be initially energized from the output side of the alternator when the system is started, and thereafter the movable contacts can be displaced to engage the second set of fixed contacts and supply the motor from the inverter output voltage.

Claim 5

A start-up system in which an electrical motor drives a mechanical load, comprising an alternator driven by an input shaft which varies in speed, a rectifier circuit coupled to the alternator for providing a DC voltage, an inverter connected for energization from the rectifier circuit, a relay including a winding, a set of movable contacts coupled to the electrical motor, a first set of fixed contacts coupled to the output side of the alternator, and a second set of fixed contacts coupled to the output side of the inverter, and circuit means, coupled both to the electrical motor and to the relay winding, for operating the relay and displacing the movable contacts when the speed of the electrical motor approaches rated speed.

Claim 6

A start-up system in which an electrical motor drives a mechanical load, comprising an alternator driven by an input shaft which varies in speed, a rectifier circuit coupled to the alternator for providing a DC voltage, an inverter connected for energization from the rectifier circuit, a relay including a winding, a set of movable contacts coupled to the electrical motor, a first set of fixed contacts coupled to the output side of the alternator, and a second set of fixed contacts coupled to the output side of the inverter, and circuit means, coupled both to the electrical motor and to the relay winding, for operating the relay and displacing the movable contacts when the speed of the electrical motor approaches rated speed.

Claim 7

A start-up system as claimed in claim 3, in which the circuit means includes a tachometer coupled to the electrical motor, a comparator circuit coupled to the relay winding, means for passing an electrical signal from the tachometer to a first input connection of the comparator circuit, and means for passing a reference signal to a second input connection of the comparator circuit, such that the relay is actuated when the speed-indicating signal from the tachometer equals the reference signal supplied to the comparator circuit.

Claim 8

A start-up system for an air conditioning unit installed in a car, in which an electrical motor drives a compressor in the unit, an alternator in the car driven by an input shaft which varies in speed, and a rectifier circuit coupled to the alternator for providing a DC voltage, which system includes a inverter connected for energization from the rectifier circuit, a relay including a winding, a set of movable contacts coupled to the electrical motor, a first set of fixed contacts coupled to the output side of the alternator, and a second set of fixed contacts coupled to the output side of the inverter, and a circuit arrangement for operating the relay and displacing the movable contacts when the speed of the electrical motor approaches rated speed, which arrangement includes a tachometer coupled to the electrical motor, a comparator circuit having an output portion coupled to the relay winding, means for passing an electrical signal from the tachometer to a first input connection of the comparator circuit, and means for passing a reference signal to a second input connection of the comparator circuit, such that the relay is actuated when the speed-indicating signal from the tachometer equals the reference signal supplied to the comparator circuit.

Claim 9

A start-up system for an air conditioning unit installed in a car, in which an electrical motor drives a compressor in the unit, an alternator in the car driven by an input shaft which varies in speed, and a rectifier circuit coupled to the alternator for providing a DC voltage, which system includes a inverter connected for energization from the rectifier circuit, a relay including a winding, a set of movable contacts coupled to the electrical motor, a first set of fixed contacts coupled to the output side of the alternator, and a second set of fixed contacts coupled to the output side of the inverter, and a circuit arrangement for operating the relay and displacing the movable contacts when the speed of the electrical motor approaches rated speed, which arrangement includes a tachometer coupled to the electrical motor, a comparator circuit having an output portion coupled to the relay winding, means for passing an electrical signal from the tachometer to a first input connection of the comparator circuit, and means for passing a reference signal to a second input connection of the comparator circuit, such that the relay is actuated when the speed-indicating signal from the tachometer equals the reference signal supplied to the comparator circuit.