Abstract:
A lighting device includes a rectifier circuit, a drive circuit and a current control circuit. Rectifier circuit rectifies an AC voltage into a pulsating voltage to be output. A load circuit including two or more solid light sources connected in series is connected between output terminals of rectifier circuit. The drive circuit changes a number of solid light sources emitting light, according to a change in a voltage value of the pulsating voltage, so that a period of the pulsating voltage includes: a first time period during which a part of the two or more solid light sources emits light; and a second time period during which all of the two or more solid light sources emit light. The current control circuit controls, in at least the second time period, a value of current flowing through load circuit according to an average voltage of the pulsating voltage.
Abstract:
A motor unit, which is an example of an embodiment, includes a motor including a motor shaft, a rotor fixed to the motor shaft, and a stator, and a control board, the control board being disposed with at least a part of the control board overlapping the motor when viewed in a motor axial direction. A sensor that detects a magnetic field of the motor shaft, the rotor, or a rotating body rotating together with the motor shaft, and a control element that controls the motor using detection information of the sensor, are mounted on the control board. The control board includes a signal line that connects the sensor and the control element. The signal line includes an arcuate wiring section bent to be convex in a radial direction outer side of a circle centering on a shaft core of the motor shaft.
Abstract:
An illuminating apparatus includes a first light emitter, a second light emitter which emits light including more predefined color components than light emitted by the first light emitter, and a lighting device which supplies current modulated according to a visible light communication signal, to the first light emitter. The lighting device supplies a constant current to the second light emitter, while the first light emitter is supplied with current.
Abstract:
A lighting device includes a rectifier circuit, a driver circuit and a shunt circuit. The driver circuit is configured to apply respective voltage components contained in a pulsating voltage from the rectifier circuit every period of the pulsating voltage across part and all of solid light sources in response to the pulsating voltage and respective ON voltages of light source circuits including the part and all of the solid light sources. The shunt circuit is electrically connected in parallel with a light source circuit having a lowest ON voltage of the light source circuits, and configured to set a value of an output current from the rectifier circuit to a value proportional to a value of the pulsating voltage while the pulsating voltage is less than the lowest ON voltage.
Abstract:
A control circuit is configured to convert a DC voltage that is outputted from a DC power supply to a square wave voltage by switching the switching element according to a PWM signal having a duty ratio that corresponds to a light modulation level of the light source unit, and cause the square wave voltage to be outputted to the light source unit. The control circuit includes a voltage controller configured to control an operating voltage for operating the switching element such that at least one of a rising time and a falling time of a current that flows through the switching element is 1 microsecond or more.
Abstract:
A lighting device includes a first current controller, a second current controller, and a charging current controller. The first current controller is configured to control current flowing through a light source so that the current flowing through the light source does not exceed a first predefined value. The charging current controller is configured to control current flowing through a storage element. The second current controller is configured to control current flowing through a first light source so that the current flowing through the first light source does not exceed a second predefined value.
Abstract:
A controller circuit is configured to adjust the number of light-emitting diodes that a current flows from a rectifier circuit through so that: the number of light-emitting diodes, which are lit, of the plurality of light-emitting diodes increases according to a value of a pulsating voltage during a time period that the value of the pulsating voltage increases; and the number of light-emitting diodes, which are lit, of the plurality of light-emitting diodes decreases according to the value of the pulsating voltage during a time period that the value of the pulsating voltage decreases. Light-emitting diodes, which start to emit light by a higher voltage value, of the plurality of light-emitting diodes are disposed at a position nearer to an outside of a mounting region of a substrate than light-emitting diodes, which start to emit light by a lower voltage value, of the plurality of light-emitting diodes.
Abstract:
Provided is a control circuit (modulation circuit) that receives output current determined based on a dimming signal, from a lighting device, consumes, as consumption current, part of the output current, and supplies supply current to a light-emitting element. The control circuit includes a regulator circuit that regulates the consumption current. The regulator circuit monotonously increases a magnitude of the consumption current relative to a magnitude of the output current.
Abstract:
The light source unit includes a light source circuit including N (N≧3) pairs of a light source group including one or more solid light emitting elements and a constant current circuit connected in series with the light source group to keep, constant, current flowing through the light source group, a full-wave rectification circuit for performing full-wave rectification on AC voltage, and a control circuit. The first pair is connected to the full-wave rectification circuit. The k-th (2≦k≦N) pair is connected in parallel with the constant current circuit of the (k−1)-th pair so that the light source groups of the k-th and (k−1)-th pairs are in series. The control circuit terminates operations of the constant current circuits of the N pairs or limits currents flowing through the light source groups of the N pairs in response to detection of light or a signal.
Abstract:
A lighting device includes a rectifier, a constant current regulator and a charge-discharge circuit. The constant current regulator is electrically connected in series with first and second solid-state light-emitting element arrays between a pair of output terminals of the rectifier. The constant current regulator is configured to adjust a current flowing through the second solid-state light-emitting element array to a constant current. The charge-discharge circuit is electrically connected in series with the first solid-state light-emitting element array between the pair of output terminals of the rectifier. The charge-discharge circuit includes a charge storage element, and is configured so that a charge current flows to the charge storage element through the first solid-state light-emitting element array, and so that a discharge current flows from the charge storage element to the second solid-state light-emitting element array.