Inverter circuit
First Claim
1. A three-phase bridge inverter circuit receiving electric power from a DC power supply and converting the DC power into AC power, comprising:
- six switching elements constituting said inverter;
six diodes;
a drive circuit controlling a conductive state and a cut-off state of said switching elements for different phases;
a level shift circuit for converting a signal with reference to a low potential side electrode of said DC power supply into a signal with reference to one of main electrodes of the switching elements on a high potential side among said switching elements;
means for detecting the state of said switching elements; and
means for detecting the temperature of the inverter circuit;
wherein at least said six switching elements are isolated from one another by forming them in a semiconductor region isolated by a dielectric body, all of which are formed together in the form of a monolithic IC.
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Accused Products
Abstract
A three-phase bridge inverter for controlling a motor with a variable speed includes a drive circuit therefor and an overcurrent protection circuit on one integrated chip. The inverter IC can be operated by directly inputting a direct current obtained by rectifying commercial 100 V. Thus, the inverter chip reduces the size and the weight of a system, improves the usability, lowers the cost thereof and permits mass production fabrication. Also, the life of the IC is increased by detecting current flowing through the inverter and the temperature of the chip and stopping the operation, when an abnormality is found.
95 Citations
20 Claims
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1. A three-phase bridge inverter circuit receiving electric power from a DC power supply and converting the DC power into AC power, comprising:
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six switching elements constituting said inverter; six diodes; a drive circuit controlling a conductive state and a cut-off state of said switching elements for different phases; a level shift circuit for converting a signal with reference to a low potential side electrode of said DC power supply into a signal with reference to one of main electrodes of the switching elements on a high potential side among said switching elements; means for detecting the state of said switching elements; and means for detecting the temperature of the inverter circuit; wherein at least said six switching elements are isolated from one another by forming them in a semiconductor region isolated by a dielectric body, all of which are formed together in the form of a monolithic IC. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An electric motor unit comprising an electric motor and an inverter implemented in the form of a monolithic IC device incorporated into said motor, wherein said inverter includes:
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a first group of switching elements and a second group of switching elements, an electric current flowing into said motor from said first group of switching elements and flowing out of said motor to said second group of switching elements; a drive circuit for controlling said switching elements in response to a control signal; current detecting circuit for detecting electric current flowing in said second group of switching elements; and a temperature detecting circuit for detecting a temperature of said monolithic IC device and controlling an operation state of said switching elements in accordance with the detected temperature. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification