Power supply apparatus capable of detecting abnormality of current flowing through drive circuit
First Claim
1. A power supply apparatus, comprising:
- a CPU having prescribed operation cycles including a shortest operation cycle;
a power supply;
a drive circuit for receiving supply of power from said power supply and driving a load circuit; and
an abnormal current detection circuit for detecting abnormality in a drive current flowing through said drive circuit;
said abnormal current detection circuit includingcurrent detection means for detecting a maximum value of said drive current for each prescribed operation cycle, andabnormality determination means for determining whether the maximum value of said drive current exceeds a prescribed threshold value for each said prescribed operation cycle, and determining presence of abnormality in said drive current when detecting that the maximum value of said drive current exceeds said prescribed threshold value in each of n (n is a natural number of at least
3) consecutive cycles of said prescribed operation cycles including a first operation cycle, wherein the first operation cycle is set to the shortest operation cycle of the CPU.
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Accused Products
Abstract
A current detection unit starts sampling of a motor current at the timing when the motor current has exceeded a threshold value, and holds a maximum motor current value for each prescribed operation cycle. An abnormality determination unit determines whether the maximum motor current value is greater than the threshold value, and counts the number of times that the maximum motor current value continuously exceeds the threshold value. When the count value has reached at least 3, the abnormality determination unit generates and outputs a detection signal indicating abnormality in the motor current to a relay drive unit and a notification unit. The relay drive unit in receipt of the detection signal generates a signal to turn off the system relays. The notification unit generates and outputs a signal AL to display means outside the power supply apparatus.
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Citations
37 Claims
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1. A power supply apparatus, comprising:
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a CPU having prescribed operation cycles including a shortest operation cycle; a power supply; a drive circuit for receiving supply of power from said power supply and driving a load circuit; and an abnormal current detection circuit for detecting abnormality in a drive current flowing through said drive circuit; said abnormal current detection circuit including current detection means for detecting a maximum value of said drive current for each prescribed operation cycle, and abnormality determination means for determining whether the maximum value of said drive current exceeds a prescribed threshold value for each said prescribed operation cycle, and determining presence of abnormality in said drive current when detecting that the maximum value of said drive current exceeds said prescribed threshold value in each of n (n is a natural number of at least
3) consecutive cycles of said prescribed operation cycles including a first operation cycle, wherein the first operation cycle is set to the shortest operation cycle of the CPU. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 37)
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2. A power supply apparatus, comprising:
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a CPU having prescribed operation cycles including a shortest operation cycle; a power supply; a drive circuit for receiving supply of power from said power supply and driving a load circuit; and an abnormal current detection circuit for detecting abnormality in a drive current flowing through said drive circuit; said abnormal current detection circuit including current detection means for starting sampling of said drive current using a prescribed threshold value as a trigger and detecting a maximum value of said drive current for each prescribed operation cycle, and abnormality determination means for determining whether the maximum value of said drive current exceeds said prescribed threshold value for each said prescribed operation cycle, and determining presence of abnormality in said drive current when detecting that the maximum value of said drive current exceeds said prescribed threshold value in each of n (n is a natural number of at least
3) consecutive cycles of said prescribed operation cycles including a first operation cycle, wherein the first operation cycle is set to the shortest operation cycle of the CPU.
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19. A power supply apparatus, comprising:
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a CPU having prescribed operation cycles including a shortest operation cycle; a power supply; a drive circuit for receiving supply of power from said power supply and driving a load circuit; and an abnormal current detection circuit for detecting abnormality in a drive current flowing through said drive circuit; said abnormal current detection circuit including a current detection unit for detecting a maximum value of said drive current for each prescribed operation cycle, and an abnormality determination unit for determining whether the maximum value of said drive current exceeds a prescribed threshold value for each said prescribed operation cycle, and determining presence of abnormality in said drive current when detecting that the maximum value of said drive current exceeds said prescribed threshold value in each of n (n is a natural number of at least
3) consecutive cycles of said prescribed operation cycles including a first operation cycle, wherein the first operation cycle is set to the shortest operation cycle of the CPU. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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20. A power supply apparatus, comprising:
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a CPU having prescribed operation cycles including a shortest operation cycle; a power supply; a drive circuit for receiving supply of power from said power supply and driving a load circuit; and an abnormal current detection circuit for detecting abnormality in a drive current flowing through said drive circuit; said abnormal current detection circuit including a current detection unit for starting sampling of said drive current using a prescribed threshold value as a trigger and detecting a maximum value of said drive current for each prescribed operation cycle, and an abnormality determination unit for determining whether the maximum value of said drive current exceeds said prescribed threshold value for each said prescribed operation cycle, and determining presence of abnormality in said drive current when detecting that the maximum value of said drive current exceeds said prescribed threshold value in each of n (n is a natural number of at least
3) consecutive cycles of said prescribed operation cycles including a first operation cycle, wherein the first operation cycle is set to the shortest operation cycle of the CPU.
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Specification