Abstract: According to one embodiment, an LED lighting device comprises at least one normally-on type switching element, an output generation unit that generates DC output by an on-off operation of the switching element, a semiconductor light emitting element that is lit by the DC output generated by the output generation unit, and a driving control unit that causes the switching element to perform an off operation using a current passed through the semiconductor light emitting element.

Abstract: According to one embodiment, an LED lighting device comprises at least one normally-on type switching element, an output generation unit that generates DC output by an on-off operation of the switching element, a semiconductor light emitting element that is lit by the DC output generated by the output generation unit, and a driving control unit that causes the switching element to perform an off operation using a current passed through the semiconductor light emitting element.

Abstract: According to one embodiment, an LED lighting device comprises at least one normally-on type switching element, an output generation unit that generates DC output by an on-off operation of the switching element, a semiconductor light emitting element that is lit by the DC output generated by the output generation unit, and a driving control unit that causes the switching element to perform an off operation using a current passed through the semiconductor light emitting element.

Abstract: According to an embodiment of the invention, there is provided a switching power supply device including an integrated body and a plurality of external terminals. In the integrated body, a first switching element, a constant current element, and a diode are connected in series. The plurality of external terminals include a first external terminal connected to a main terminal of an element disposed on one end side of the integrated body and a second external terminal connected to a main terminal of an element disposed on another end side of the integrated body.

Abstract: A switching power supply apparatus according to an embodiment includes a switching element, an inductor, a drive circuit, a mounting substrate, and an insulating substrate. The switching element is connected between a power supply and a lighting load. The inductor is connected in series to the switching element. The drive circuit controls the switching element, converts a voltage supplied from the power supply, and is mounted on the mounting substrate. The insulating substrate is thermally connected to the switching element, and has thermal conductivity higher than the mounting substrate.

Abstract: According to one embodiment, a power supply device includes a rectifier circuit, a smoothing capacitor, and a normally on type transistor. The rectifier circuit is configured to rectify an alternating current supplied from a voltage source. The smoothing capacitor is charged by an output current output from the rectifier circuit. The normally on type transistor is connected between the rectifier circuit and the smoothing capacitor in series and is configured to limit an output current value of the rectifier circuit during a voltage input from the voltage source to an output current value higher than an output current value of the rectifier circuit during a steady operation.

Abstract: According to one embodiment, there is provided a power supply device includes a DC-DC converter and a protection circuit. The DC-DC converter includes a switching element of a normally on type, a current control element of the normally on type connected to the switching element in series and configured to control an electric current flowing to the switching element, and a rectifying element connected to the current control element in series. The DC-DC converter converts, according to ON and OFF of the switching element, an input first direct-current voltage into a second-direct current voltage, which has an absolute value different from an absolute value of the first direct-current voltage, and supplies the second direct-current voltage to a load. When an electric current equal to or larger than a predetermined value flows to the switching element and the current control element, the protection circuit cuts off the electric current.

Abstract: According to one embodiment, a power supply device includes a terminal connected to an output of a dimmer, a rectifier circuit, a switching circuit including an inductor, a switching element connected to the inductor in series, and a first rectifying element and configured to change the switching element to an ON state to feed an output current of the rectifier circuit to the inductor, after the dimmer changes from a non-conduction state to a conduction state, when the dimmer is a dimmer of a phase control type, and configured to change the switching element to the ON state to feed the output current of the rectifier circuit to the inductor, after the dimmer changes from the non-conduction state to the conduction state, when the dimmer is a dimmer of an anti-phase control type, and a DC-DC converter configured to convert the output voltage of the switching circuit.

Abstract: According to one embodiment, a power supply device includes a first inductor, a current control section configured to limit a current value of an electric current flowing through the first inductor to a predetermined current value, the current control section including a first switching element of a normally on type and a resistor connected to a main terminal of the first switching element, a rectifying element connected to the current control section in series, and a second inductor magnetically coupled to the first inductor. The second inductor is configured to induce a voltage for turning on the current control section, when the electric current of the first inductor increases, to induce a voltage for turning off the current control section, when the electric current of the first inductor decreases, and to supply the induced voltage to a control terminal of the current control section.

Abstract: A rectifying circuit according to an embodiment includes a first rectifying portion and a second rectifying portion. The first rectifying portion has a positive temperature coefficient. The second rectifying portion has a negative temperature coefficient, is connected in parallel to the first rectifying portion, and has a forward voltage-forward current curve intersecting a forward voltage-forward current curve of the first rectifying portion.

Abstract: According to one embodiment, a power supply device includes a conductive first mounting board, a first switching element, a current control element, and a second switching element. The first switching element is mounted on the first mounting board. The current control element is mounted on the first mounting board, includes a main terminal connected to the first mounting board, is connected to the first switching element in series, and is configured to limit an electric current of the first switching element. The second switching element is connected to the current control element in series. An electric current flows to the second switching element when the first switching element is off.

Abstract: An LED lighting device including a DC power source circuit, a high frequency generation circuit which includes an inverter circuit having switching elements and a resonance circuit having a series-connected inductor and condenser, in which the switching elements are on-off controlled by a no-load resonance frequency of the resonance circuit, and DC voltage input from the DC power source circuit is converted into a high frequency AC voltage, a rectification smoothing circuit having an input side which is connected between both edges of the condenser or both edges of the inductor; and a light emitting diode series connected to an output side of the rectification smoothing circuit.

Abstract: According to one embodiment, a power supply for lighting includes an output element. The output element is connected between a power supply and a lighting load, and configured to be capable of being switched to a switching operation repeating an ON state and an OFF state and an ON continuation operation continuing the ON state.

Abstract: According to one embodiment, a power supply device includes a substrate, a first inductor, and a second inductor. The substrate has a first surface and a second surface on opposite side from the first surface. The first inductor includes a first coil having a coil center axis substantially parallel to a first direction, is used for a switching circuit for controlling power supplied to a load, and is mounted on the first surface of the substrate. The second inductor includes a second coil having a coil center axis substantially parallel to the first direction, is electrically connected to the first inductor, and is mounted on the second surface of the substrate. As viewed in a direction orthogonal to the first surface, position of the first coil of the first inductor does not overlap position of the second coil of the second inductor.

Abstract: A power supply apparatus of an embodiment includes a first filter, a second filter, and a switching power supply. The first filter and the second filter attenuate a common mode current to a level lower than a normal mode current. The switching power supply is connected between the first filter and the second filter, and supplies electric power to an illumination load via the second filter.

Abstract: According to one embodiment, a detection circuit including first and second comparators and a determining unit is provided. The first comparator includes a first input terminal for inputting a first detection voltage, a second input terminal for inputting a first threshold voltage, and a first output terminal configured to output a first output signal. The second comparator includes a third input terminal for inputting a second detection voltage, a fourth input terminal for inputting a second threshold voltage higher than the first threshold voltage, and a second output terminal configured to output a second output signal. The determining unit is configured to determine the presence or absence of conduction angle control of an AC voltage and whether the conduction angle control is a phase control system or an opposite phase control system on the basis of a time difference between the first output signal and the second output signal.

Abstract: A lighting power source according to an embodiment includes a rectification circuit, a smoothing capacitor, a waveform shaping circuit, and a DC-DC converter. The rectification circuit rectifies an AC voltage input thereto. The waveform shaping circuit is connected between the rectification circuit and the smoothing capacitor, performs a switching operation to repeat an ON state and an OFF state when the voltage output from the rectification circuit is relatively high, continues to be in the ON state to allow the current to flow to the rectification circuit when the voltage output from the rectification circuit is relatively low. The DC-DC converter converts a voltage charged in the smoothing capacitor.

Abstract: According to one embodiment, a rectifying circuit includes a diode, a switching element, a capacitor and an auxiliary winding. The diode is connected between a first terminal and a second terminal while a direction directed from the second terminal to the first terminal is a forward direction. The switching element includes a first main electrode connected to the first terminal, a second main electrode connected to a cathode of the diode, and a gate electrode connected to an anode of the diode. The auxiliary winding is magnetically coupled to an inductor. The auxiliary winding is connected to the gate electrode through the capacitor, and is connected to the second main electrode of the switching element and the cathode of the diode.

Abstract: An integrated switching power supply device includes a series-connected body, a driving control element, and external terminals. In the series-connected body, a switching element, a constant current element, and a diode are connected in series. The driving control element controls to drive the constant current element. The external terminals include first to seventh external terminals. The first and second external terminals are connected to main terminals of elements of the series-connected body. The third external terminal is connected to a connection point of main terminals of the switching element or the constant current element and a main terminal of the diode. The fourth external terminal is connected to a control terminal of the switching element. The fifth external terminal supplies electric power to the driving control element. The sixth external terminal inputs reference potential. The seventh external terminal inputs a signal to the driving control element.

Abstract: According to one embodiment, provided is a power supply circuit including a power conversion unit, a controller, and an integrated circuit. The power conversion unit converts an AC voltage into a different voltage. The integrated circuit includes a current regulator that can switch between a first state in which a part of a current flowing through the power supply path flows to an input terminal and a second state in which a current flowing to the input terminal is lower than that of the first state, a controller power supply that converts a voltage into a driving voltage and supplies the driving voltage to the controller, a connection terminal for connecting an auxiliary power supply used for generating the driving voltage, and a protection circuit that blocks or decreases, when an auxiliary power supply voltage of the auxiliary power supply decreases, a current flowing to the input terminal.