Abstract: This description relates to an electrical power converter including a series connection of two transistors, and provides a technology for suppressing increase in electrical current flowing through the transistors when the two transistors are turned on at the same time for some defective reason. An electrical power converter disclosed herein includes a series connection of a first transistor and a second transistor. The electrical power converter includes a clamp circuit configured to inhibit an abnormal rise in gate voltage, which is provided in at least either the first transistor or the second transistor. The clamp circuit includes a diode and a capacitor. The diode has an anode connected with a gate of the transistor. The capacitor has one electrode connected with a cathode of the diode and the other electrode connected with an emitter of the transistor.

Abstract: A resonance type non-contact charging apparatus is disclosed. A charger of the apparatus receives the high frequency power from a secondary side resonance coil of the apparatus. A power ratio detecting section of the apparatus detects the ratio of the reflected power from a primary side resonance coil to the high frequency power source with respect to the output power from the high frequency power source to the primary side resonance coil. A stop control section of the apparatus stops the high frequency power source when the ratio detected by the power ratio detecting section becomes greater than or equal to a predetermined threshold value.

Abstract: A non-contact power transmission apparatus having a resonance system is disclosed. The resonance system includes a primary coil to which an alternating-current voltage from an alternating-current source is applied, a primary-side resonance coil, a secondary-side resonance coil, and a secondary coil to which a load is connected. The impedance of the primary coil is set such that the output impedance of the alternating-current source and the input impedance of the resonance system are matched to each other.

Abstract: A non-contact power transmission apparatus having an AC power source and a resonance system is disclosed. The resonance system has a primary coil connected to the AC power source, a primary side resonance coil, a secondary side resonance coil, a secondary coil, and a load connected to the secondary coil. The primary side resonance coil is separated from the primary coil in an axial direction by a first distance, and the secondary coil is separated from the secondary side resonance coil in the axial direction by a second distance. At least one of the first distance and the second distance is adjusted to be a distance that is determined in advance in accordance with the impedance of the load so that the power transmission efficiency is maintained at a proper value.

Abstract: A resonance type non-contact charging device includes a high frequency power source, a primary side resonant coil, a secondary side resonant coil, a charger, a secondary battery, and a stop control unit. The primary side resonant coil receives supply of high frequency electric power from the high frequency power source. The secondary side resonant coil is arranged apart from the primary side resonant coil in a non-contact manner. The secondary side resonant coil receives electric power from the primary side resonant coil through magnetic field resonance between the primary side resonant coil and the secondary side resonant coil. The charger receives supply of high frequency electric power from the secondary side resonant coil. The secondary battery is connected to the charger. The stop control unit stops the high frequency power source before stopping the charger when charging is to be stopped.

Abstract: A resonance type non-contact charging device includes a high frequency power source, a primary side resonant coil, a secondary side resonant coil, a charger, a secondary battery, and a stop control unit. The primary side resonant coil receives supply of high frequency electric power from the high frequency power source. The secondary side resonant coil is arranged apart from the primary side resonant coil in a non-contact manner. The secondary side resonant coil receives electric power from the primary side resonant coil through magnetic field resonance between the primary side resonant coil and the secondary side resonant coil. The charger receives supply of high frequency electric power from the secondary side resonant coil. The secondary battery is connected to the charger. The stop control unit stops the high frequency power source before stopping the charger when charging is to be stopped.

Abstract: A resonance type non-contact charging device includes a high frequency power source, a primary side resonant coil, a secondary side resonant coil, a charger, a secondary battery, and a stop control unit. The primary side resonant coil receives supply of high frequency electric power from the high frequency power source. The secondary side resonant coil is arranged apart from the primary side resonant coil in a non-contact manner. The secondary side resonant coil receives electric power from the primary side resonant coil through magnetic field resonance between the primary side resonant coil and the secondary side resonant coil. The charger receives supply of high frequency electric power from the secondary side resonant coil. The secondary battery is connected to the charger. The stop control unit stops the high frequency power source before stopping the charger when charging is to be stopped.

Abstract: A resonance type non-contact charging device includes a high frequency power source, a primary side resonant coil, a secondary side resonant coil, a charger, a secondary battery, and a stop control unit. The primary side resonant coil receives supply of high frequency electric power from the high frequency power source. The secondary side resonant coil is arranged apart from the primary side resonant coil in a non-contact manner. The secondary side resonant coil receives electric power from the primary side resonant coil through magnetic field resonance between the primary side resonant coil and the secondary side resonant coil. The charger receives supply of high frequency electric power from the secondary side resonant coil. The secondary battery is connected to the charger. The stop control unit stops the high frequency power source before stopping the charger when charging is to be stopped.

Abstract: A non-contact power transmission apparatus is disclosed. The non-contact power transmission apparatus includes an AC power source, a primary coil, a primary side resonance coil, a secondary side resonance coil, a secondary coil, a voltage measuring section, and a distance calculating section. AC voltage of the AC power source is applied to the primary coil. A load is connected to the secondary coil. The voltage measuring section measures the voltage of the primary coil. The distance calculating section calculates the distance between the primary side resonance coil and the secondary side resonance coil based on the voltage measured by the voltage measuring section.

Abstract: A resonance type non-contact charging device includes a high frequency power source, a primary side resonant coil, a secondary side resonant coil, a charger, a secondary battery, and a stop control unit. The primary side resonant coil receives supply of high frequency electric power from the high frequency power source. The secondary side resonant coil is arranged apart from the primary side resonant coil in a non-contact manner. The secondary side resonant coil receives electric power from the primary side resonant coil through magnetic field resonance between the primary side resonant coil and the secondary side resonant coil. The charger receives supply of high frequency electric power from the secondary side resonant coil. The secondary battery is connected to the charger. The stop control unit stops the high frequency power source before stopping the charger when charging is to be stopped.

Abstract: A non-contact power transmission device includes an alternating current power supply, a resonant system, a load, an impedance measuring section and an analyzing section. The resonant system has a primary coil connected to the alternating current power supply, a primary-side resonant coil, a secondary-side resonant coil and a secondary coil. The load is connected to the secondary coil. The impedance measuring section can measure the input impedance of the resonant system. The analyzing section analyzes the measurement results obtained from the impedance measuring section.

Abstract: A resonance type non-contact charging device includes a high frequency power source, a primary side resonant coil, a secondary side resonant coil, a charger, a secondary battery, and a stop control unit, The primary side resonant coil receives supply of high frequency electric power from the high frequency power source. The secondary side resonant coil is arranged apart from the primary side resonant coil in a non-contact manner. The secondary side resonant coil receives electric power from the primary side resonant coil through magnetic field resonance between the primary side resonant coil and the secondary side resonant coil. The charger receives supply of high frequency electric power from the secondary side resonant coil. The secondary battery is connected to the charger. The stop control unit stops the high frequency power source before stopping the charger when charging is to be stopped.

Abstract: A non-contact power transmission device is disclosed. The resonant system includes a primary coil connected to the AC power source, a primary resonance coil, a secondary resonance coil, and a secondary coil is connected to the load. When the relationship between an input impedance of the resonant system and a frequency of an AC voltage of the AC power source is shown in a graph, the frequency of the AC voltage of the AC power source is set between a first frequency at which the input impedance has a local maximum value, and a second frequency that is greater than the first frequency and at which the input impedance has a local minimum value.

Abstract: Disclosed is a non-contact power transmission apparatus provided with an AC power source and a resonant system. The resonant system has a primary coil that is connected with the AC power source, a primary-side resonance coil, a secondary-side resonance coil, a secondary coil and a load that is connected with the secondary coil. In addition, the non-contact power transmission apparatus is provided with a state detection unit and a variable-impedance circuit. The state detection unit detects the state of the resonant system. The variable-impedance circuit is constructed so as to adjust its own impedance in accordance with the state of the resonant system detected by the state detection unit, in such a way that the input impedance and the output impedance at the resonant frequency of the resonant system are matching.

Abstract: In a protection circuit connected, via lines including an inductance component, to a circuit to be protected, a first transistor is arranged on a path to ground from a connection point of the protection circuit and the line. A second transistor is arranged on a path to ground from a connection point of the circuit to be protected and the line, and extracts, from a connection point, a current corresponding to a current flowing in the first transistor. The first and the second transistors are NPN bipolar transistors having a base and an emitter are commonly connected. A resistor is connected between the base and the emitter of the first transistor, and a diode is connected between the base and a collector.

Abstract: A non-contact power transmission apparatus is disclosed. The non-contact power transmission apparatus includes an AC power source, a primary coil, a primary side resonance coil, a secondary side resonance coil, a secondary coil, a voltage measuring section, and a distance calculating section. AC voltage of the AC power source is applied to the primary coil. A load is connected to the secondary coil. The voltage measuring section measures the voltage of the primary coil. The distance calculating section calculates the distance between the primary side resonance coil and the secondary side resonance coil based on the voltage measured by the voltage measuring section.

Abstract: A non-contact power transmission apparatus having an AC power source and a resonance system is disclosed. The resonance system has a primary coil connected to the AC power source, a primary side resonance coil, a secondary side resonance coil, a secondary coil, and a load connected to the secondary coil. The primary side resonance coil is separated from the primary coil in an axial direction by a first distance, and the secondary coil is separated from the secondary side resonance coil in the axial direction by a second distance. At least one of the first distance and the second distance is adjusted to be a distance that is determined in advance in accordance with the impedance of the load so that the power transmission efficiency is maintained at a proper value.

Abstract: A step-up/step-down regulator circuit wherein a switch has a terminal connected to an end of an inductor, another terminal grounded, and a control terminal connected to an end of a switch. In this way, performing an open/close control of the switch can indirectly perform an open/close control of the switch, thereby solving the problem that the structure and operation of a switch control circuit will be complicated when the switching between step-up and step-down operation is realized.

Abstract: A resonance type non-contact charging apparatus is disclosed. A charger of the apparatus receives the high frequency power from a secondary side resonance coil of the apparatus. A power ratio detecting section of the apparatus detects the ratio of the reflected power from a primary side resonance coil to the high frequency power source with respect to the output power from the high frequency power source to the primary side resonance coil. A stop control section of the apparatus stops the high frequency power source when the ratio detected by the power ratio detecting section becomes greater than or equal to a predetermined threshold value.

Abstract: A non-contact power transmission apparatus having a resonance system is disclosed. The resonance system includes a primary coil to which an alternating-current voltage from an alternating-current source is applied, a primary-side resonance coil, a secondary-side resonance coil, and a secondary coil to which a load is connected. The impedance of the primary coil is set such that the output impedance of the alternating-current source and the input impedance of the resonance system are matched to each other.