Power transmission device, electronic instrument, and waveform monitoring circuit
First Claim
1. A power transmission device included in a non-contact power transmission system that transmits power to a power reception device by electromagnetically coupling a primary coil and a secondary coil to transmit power to a load of the power reception device, the power transmission device comprising:
- a waveform monitoring circuit that includes a first rectifier circuit and generates and outputs a waveform-monitoring induced voltage signal based on a coil end signal of the primary coil; and
a power transmission control device that controls a power transmission driver that drives the primary coil, the power transmission control device receiving the waveform-monitoring induced voltage signal and detecting a waveform of the induced voltage signal to detect a power-reception-side load state,the first rectifier circuit including;
a first resistor that is a current-limiting resistor provided between a coil end node where the coil end signal of the primary coil is generated and a first monitoring node where a first induced voltage signal that is the waveform-monitoring induced voltage signal is generated;
a first diode provided between the first monitoring node and a high-potential-side power supply node, a forward direction of the first diode being a direction from the first monitoring node to the high-potential-side power supply node; and
a second diode provided between the first monitoring node and a low-potential-side power supply node, a forward direction of the second diode being a direction from the low-potential-side power supply node to the first monitoring node.
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Accused Products
Abstract
A power transmission device of a non-contact power transmission system includes a waveform monitoring circuit that generates and outputs a waveform-monitoring induced voltage signal based on a coil end signal of a primary coil, and a power transmission control device that controls a power transmission driver that drives the primary coil, the power transmission control device receiving the waveform-monitoring induced voltage signal and detecting a change in waveform of the induced voltage signal to detect a power-reception-side load state. The waveform monitoring circuit includes a first rectifier circuit having a limiter function, the first rectifier circuit including a current-limiting resistor provided between a coil end node where the coil end signal of the primary coil is generated and a monitoring node where the waveform-monitoring induced voltage signal is generated, performing a limiter operation that clamps the induced voltage signal at a high-potential-side power supply voltage, and subjecting the induced voltage signal to half-wave rectification.
39 Citations
17 Claims
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1. A power transmission device included in a non-contact power transmission system that transmits power to a power reception device by electromagnetically coupling a primary coil and a secondary coil to transmit power to a load of the power reception device, the power transmission device comprising:
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a waveform monitoring circuit that includes a first rectifier circuit and generates and outputs a waveform-monitoring induced voltage signal based on a coil end signal of the primary coil; and a power transmission control device that controls a power transmission driver that drives the primary coil, the power transmission control device receiving the waveform-monitoring induced voltage signal and detecting a waveform of the induced voltage signal to detect a power-reception-side load state, the first rectifier circuit including; a first resistor that is a current-limiting resistor provided between a coil end node where the coil end signal of the primary coil is generated and a first monitoring node where a first induced voltage signal that is the waveform-monitoring induced voltage signal is generated; a first diode provided between the first monitoring node and a high-potential-side power supply node, a forward direction of the first diode being a direction from the first monitoring node to the high-potential-side power supply node; and a second diode provided between the first monitoring node and a low-potential-side power supply node, a forward direction of the second diode being a direction from the low-potential-side power supply node to the first monitoring node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A power transmission device included in a non-contact power transmission system that transmits power to a power reception device by electromagnetically coupling a primary coil and a secondary coil to transmit power to a load of the power reception device, the power transmission device comprising:
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a waveform monitoring circuit that includes a first rectifier circuit and generates and outputs a waveform-monitoring induced voltage signal based on a coil end signal of the primary coil; and a power transmission control device that controls a power transmission driver that drives the primary coil, the power transmission control device receiving the waveform-monitoring induced voltage signal and detecting a waveform of the induced voltage signal to detect a power-reception-side load state, the first rectifier circuit including; a first resistor that is a current-limiting resistor provided between a coil end node where the coil end signal of the primary coil is generated and a first monitoring node where a first induced voltage signal that is the waveform-monitoring induced voltage signal is generated; and a Zener diode provided between the first monitoring node and a low-potential-side power supply node, a forward direction of the Zener diode being a direction from the low-potential-side power supply node to the first monitoring node.
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17. A power transmission device included in a non-contact power transmission system that transmits power to a power reception device by electromagnetically coupling a primary coil and a secondary coil to transmit power to a load of the power reception device, the power transmission device comprising:
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a waveform monitoring circuit that includes a first rectifier circuit and generates and outputs a waveform-monitoring induced voltage signal based on a coil end signal of the primary coil; and a power transmission control device that controls a power transmission driver that drives the primary coil, the power transmission control device receiving the waveform-monitoring induced voltage signal and detecting a waveform of the induced voltage signal to detect a power-reception-side load state, the first rectifier circuit including; a first capacitor provided between a first node and a coil end node where the coil end signal of the primary coil is generated; a first resistor that is a current-limiting resistor provided between the first node and a first monitoring node where a first induced voltage signal that is the waveform-monitoring induced voltage signal is generated; a first diode provided between the first monitoring node and a high-potential-side power supply node, a forward direction of the first diode being a direction from the first monitoring node to the high-potential-side power supply node; and a second diode provided between the first node and a low-potential-side power supply node, a forward direction of the second diode being a direction from the low-potential-side power supply node to the first node.
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Specification