Abstract: According to one embodiment, a switching power supply device includes a direct-current power supply and a switching operation conversion circuit. The switching operation conversion circuit is connected to the direct-current power supply, and includes an inductor, a switching element, a diode, a gate drive circuit, an input end and an output end. The switching element allows an increasing current to flow to the inductor from the direct-current power supply at an on time of the switching element. The diode allows a decreasing current to flow to the inductor at an off time of the switching element. The gate drive circuit controls a gate voltage of the switching element to turns off the switching element when the increasing current reaches a saturated state relative to a source-drain voltage of the switching element. The input end is connected to the direct-current power supply. The output end is connected with a load.

Abstract: According to one embodiment, a switching power-supply device includes a switching element, a constant current element, a rectifying element, first and second inductors, and a constant voltage circuit. The switching element supplies, when the switching element is on, a power-supply voltage of a direct-current power supply to and feeds an electric current to the first inductor. The constant current element is connected to the switching element in series and turns off the switching element when the electric current of the switching element exceeds a predetermined current value. The rectifying element is connected to any one of the switching element and the constant current element in series. The second inductor is magnetically coupled to the first inductor and supplies induced potential to a control terminal of the switching element. The constant voltage circuit applies control potential to a control terminal of the constant current element.

Abstract: Disclosed is an interface circuit including a rectifier circuit, a detection circuit, a first circuit, and a second circuit. The rectifier circuit rectifies an AC voltage input between a pair of input terminals. The detection circuit detects the AC voltage and outputs the result as a detection voltage. The first circuit is controlled to be turned on or off on the basis of an input first control signal, to cause a first current to flow between the input terminals in an on state and to cut off the first current in an off state. The second circuit is controlled to be turned on or off on the basis of an input second control signal, to allow a second current greater than the first current to flow between the input terminals in an on state and to cut off the second current in an off state.

Abstract: A detection circuit according to embodiments includes a first circuit and a second circuit. The first circuit is turned OFF when an AC voltage to be input to a pair of input terminals is smaller than a prescribed value, and is turned ON when the AC voltage is equal to or higher than the prescribed value. The second circuit detects whether the AC voltage is an AC voltage leading-edge controlled by a dimmer, an AC voltage trailing-edge controlled by the dimmer, or an AC voltage having a continuous phase on the basis of at least one of the value of voltage and a gradient of the first circuit when the first circuit is turned ON while the first circuit is in the OFF state.

Abstract: According to one embodiment, a power supply device includes a full-wave rectifier, a power converting circuit, and a partial smoothing circuit. The power converting circuit converts an output of the full-wave rectifier into a direct-current voltage according to a switching action of a switching element. The partial smoothing circuit includes, in series, a capacitor and a first diode connected in polarity opposite to output polarity of the full-wave rectifier. The partial smoothing circuit is provided on an output side of the full-wave rectifier in parallel to the power converting circuit. In the partial smoothing circuit, the capacitor is charged according to the switching action of the switching element of the power converting circuit. The partial smoothing circuit supplies charged electric of the capacitor to the power converting circuit via the first diode in a trough portion of an output voltage of the full-wave rectifier.

Abstract: A switching power source device includes: a direct power source; and a chopper circuit including a pair of input terminals connected to the direct power source and a pair of output terminals connected to a load, the chopper circuit including a first inductor, a second inductor magnetically coupled to the first inductor, a third inductor connected to the first inductor, a switching element causing an augmented current to flow from the direct power source to the first and third inductors while turned on, a constant current element connected to the switching element in series, a rectifier element causing a reduced current to flow through the first and third inductors while the switching element is turned off, and a drive circuit controlling and turning off a gate voltage of the switching element after the switching element is turned on and the augmented current reaches a constant current element saturated state.

Abstract: According to one embodiment, a power supply for lighting includes a rectifying circuit, a smoothing capacitor, and a current control circuit. The rectifying circuit rectifies a phase-controlled alternating-current voltage supplied to between a pair of input terminals. The smoothing capacitor is connected to a high-potential terminal and a low-potential terminal of the rectifying circuit. A first electric current flows to the current control circuit in a period when an absolute value of the alternating-current voltage is lower than a specified value. After a second electric current larger than the first electric current flows when the absolute value of the alternating-current voltage increases to be equal to or larger than the specified value, the current control circuit is shut off to reduce a current value to be smaller than the second electric current until the absolute value of the alternating-current voltage decreases to be lower than the specified value.

Abstract: A power factor control circuit of an embodiment includes an inductor, a switching element, a constant current element, a feedback coil, and a control circuit. The switching element is connected to one end of the inductor in series, performs a switching operation of repeating an on-state and an off-state when an input voltage is relatively high, continues the on-state when the input voltage is relatively low, and causes an input current to flow through the inductor. The constant current element is connected to the switching element in series and limits the current of the switching element. The feedback coil is magnetically coupled to the inductor, supplies a voltage to a control terminal of the switching element, and controls the switching element. The control circuit controls a constant current value of the constant current element depending on the input voltage.

Abstract: An LED lighting device includes light emitting diode, a current control circuit having a first series circuit of first and second switching elements, a second series circuit of third and fourth switching elements, and a condenser, which is configured so that the first and second series circuits are parallel connected and the condenser is connected between a connection point of the first and second switching elements and a connection point of the third and fourth switching elements, and a control circuit for alternatively on-off controlling a pair of the first and fourth switching elements and a pair of the second and third switching elements.

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: 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: A lighting power source according to an embodiment includes a rectifying circuit, a smoothing capacitor, a reference voltage generating circuit, and a DC-DC converter. The rectifying circuit rectifies an AD voltage input thereto. The smoothing capacitor smoothes an output from the rectifying circuit. The reference voltage generating circuit generates a reference voltage on the basis of at least any one of an output voltage of the rectifying circuit and a voltage from the smoothing capacitor. The DC-DC converter includes an output element and a constant current element, and converts the voltage of the smoothing capacitor. The output element receives a supply of a voltage of the smoothing capacitor, oscillates by performing a switching operation which repeats an ON state and an OFF state when the reference voltage is relatively high, and continues the ON state when the reference voltage is relatively low.

Abstract: According to one embodiment, a luminaire includes a light source that generates heat, a dome inside of which the light source is accommodated, and a globe covering the light source through the dome. At least part of the dome and at least part of the globe are translucent or transparent. A liquid is sealed in a space formed between the dome and the globe.

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: 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: A switching power supply includes a switching element, a constant current element, a rectifying element, a first inductor, a second inductor, and a control circuit. If the switching element is on, the switching element supplies a power supply voltage to the first inductor and feeds an electric current. The constant current element turns off the switching element if the electric current of the switching element exceeds a predetermined upper limit. The rectifying element feeds the electric current of the first inductor if the switching element is turned off. The second inductor supplies the induced potential to a control terminal of the switching element. The control circuit supplies a pulse-like potential to a control terminal of the constant current element and outputs if an average of the potential is lower than a lower limit.

Abstract: A switching power supply includes a transformer, a resonant capacitor, a pair of switching elements, an inductor, and a rectifying element. The transformer includes a first winding, a second winding, and a third winding. The resonant capacitor is connected to both ends of the first winding. The switching elements are normally-on elements and alternately turned off according to a voltage induced in the third winding. Each of the switching elements includes a first main terminal, a second main terminal, and a control terminal. The inductor supplies a direct-current power supply voltage between the middle point of the first winding and the each first main terminal of the switching elements. The rectifying element rectify a voltage induced in the second winding.

Abstract: A switching power supply includes a first switching element, a rectifying element, a first inductor and a second inductor. The first switching element supplies a power supply voltage to the first inductor and al lows a current to flow when the first switching element is on. The rectifying element is connected in series to the first switching element, and allows a current of the first inductor to flow when the first switching element is turned off. The second inductor is electromagnetically coupled to the first inductor, a potential to turn on the first switching element is induced when the current of the first inductor increases, and a potential to turn off the first switching element is induced when the current of the first inductor decreases. The induced potential is supplied to a control terminal of the first switching element. The rectifying element includes a diode and a second switching element.

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 switching power supply device includes a direct-current power supply and a switching operation conversion circuit. The switching operation conversion circuit is connected to the direct-current power supply, and includes an inductor, a switching element, a diode, a gate drive circuit, an input end and an output end. The switching element allows an increasing current to flow to the inductor from the direct-current power supply at an on time of the switching element. The diode allows a decreasing current to flow to the inductor at an off time of the switching element. The gate drive circuit controls a gate voltage of the switching element to turns off the switching element when the increasing current reaches a saturated state relative to a source-drain voltage of the switching element. The input end is connected to the direct-current power supply. The output end is connected with a load.