Switching device and related operating method
AssigneesDenso Corporation, Nippon Soken, Inc.
InventorsShinya Goto, Koji Kawasaki, Keiji Shigeoka
Life of this patent
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Abstract
A switching device 30 and a related operating method are disclosed for generate a train of drive pulses under a basic pattern for a repetition cycle time T. The train of drive pulses has leading edges shifted from basic time periods T1 by shift amounts Φ0 to Φ02, respectively, which are different from each other, whereby switching frequencies, occurring based on the leading edges of the drive pulses, are spread. A spread frequency, which is a inverse number of the cycle time T of the basic pattern, is set to be higher than an audible frequency.
Claims19
A switching device for repeatedly turning a switching power element on and off, comprising:
- a memory storing a basic pattern;
- and
- a drive pulse generator configured to generate a train of drive pulses under the basic pattern, stored in the memory, for a repetition cycle time having a plurality of basic time periods;
- wherein the drive pulses have leading edges and trailing edges at least one of which are shifted from beginnings of the basic time periods by different shift amounts, respectively, and the basic pattern includes an inverse number of the repetition cycle time laying in a value away from an audible frequency band when switching frequencies and associated harmonics, arising from at least one of the leading edges and the trailing edges of the drive pulses, discontinuously overlap a given frequency for which noise suppression needs to be taken.
A method of operating a switching power element comprising:
- preparing the switching power element;
- and
- applying the switching power element with a train of drive pulses under a basic pattern for a repetition cycle time having a plurality of basic dine periods;
- the drive pulses having leading edges and trailing edges at least one of which are shifted from beginnings of the basic time periods by different shift amounts, respectively, and the basic pattern including an inverse number of the repetition cycle time laying in a value away from an audible frequency band when switching frequencies and associated harmonics, arising from at least one of the leading edges and the trailing edges of the drive pulses, discontinuously overlap a given frequency for which noise suppression needs to be taken.
The switching device according to clam 12, wherein:
- the basic pattern includes information, including the shift amounts and a sequence of the shift amounts, and offset values, and the shift amounts for the basic time periods and the offset values added to the shift amounts, respectively, which are arranged for the drive pulses.
Dependencies are inferred from the claim text.