Panasonic Intellectual Property Management Co., Ltd.

Takahiro Fukui

Toshifumi Tanaka

Kazutoshi Suganuma

Masanobu Murakami

Takahiro Ohori

Kazuya Kato

Masaaki Takamatsu

In a power supply, a first output terminal and a second output terminal are electrically connected to each other, and a first common terminal and a second common terminal are electrically connected to each other. When a value of a consumption current of a motor is equal to or smaller than a value of a maximum output current of a second constant voltage circuit, the second constant voltage circuit keeps a second voltage at a steady voltage value. When the value of the consumption current of the motor is larger than the value of the maximum output current, the second constant voltage circuit control the second voltage to have a value smaller than a value of the first voltage, and a first constant voltage circuit supplies a differential current which corresponds to a difference between the consumption current of the motor and the maximum output current of the second constant voltage circuit.

Power supply, lamp, and vehicle

A lighting device includes an output adjustment circuit, a smoothing circuit and a control circuit. The smoothing circuit receives a binary rotation detection signal according to the rotation of a fan and smooths the rotation detection signal to produce a smoothed signal. The control circuit detects a rotation malfunction of the fan when the smoothed signal is greater than or equal to an upper limit threshold over first predetermined time or when the smoothed signal is smaller than or equal to a lower limit threshold over second predetermined time.

Power supply, lighting device, headlight device and vehicle

A lighting device includes a power converter and a controller. The power converter includes a transformer having primary, secondary and tertiary windings, and a switching device electrically connected in series with the primary winding. The controller is configured to measure a signal simulating a primary current flowing through the primary winding based on a voltage occurring across the tertiary winding and detect timing for turning the switching device off based on the signal simulating the primary current.

Lighting device, headlight device with the same, and vehicle

A lighting device includes a power converter, a second switching element and a microcomputer. The power converter is configured to convert DC power that is received from a power supply, and supply an output obtained by the conversion to a load. The second switching element is configured to short-circuit at least one LED of a plurality of LEDs, as part of the load. The microcomputer is configured to control the power converter, and control switching on/off of the second switching element. The microcomputer is configured to reduce an output current of the power converter, in a case where a power supply voltage of the battery is a reference voltage or less. A reduction amount of the output current in an on-state of the second switching element is lower than the reduction amount of the output current in an off-state of the second switching element.

Lighting device, headlight apparatus using the same, and vehicle using the same

The lighting device includes a control circuit performing dimming control of dimming a light source device according to a desired dimming level. In the dimming control, the control circuit sets a desired current value of amplitude control to a value corresponding to the desired dimming level, and set a desired duty cycle of pulse width modulation control to a predetermined value associated with a dimming subrange containing the desired dimming level, of multiple different dimming subranges of a total dimming range of the light source device. The predetermined value is a duty cycle allowing luminance of the light source device to be equal to upper limit luminance of the associated dimming subrange under a condition where the current value of the current of the light source device is a maximum value.

Lighting device, vehicle illumination device, and vehicle

A lighting device includes first to third output terminals, a power converter, a bypass switch, and a controller. A first light source is connected between the first and third output terminals. A second light source is connected between the second and third output terminals. The bypass switch is connected between the second and third output terminals. The controller switches the bypass switch between ON-state and OFF-state. The controller controls the power converter to adjust an output current. The controller includes a voltage meter for measuring a voltage corresponding to an output voltage of the power converter. The controller compares a measured voltage of the voltage meter with a first threshold voltage while keeping the bypass switch in OFF-state. The controller compares the measured voltage with a second threshold voltage while keeping the bypass switch in ON-state. The second threshold voltage is smaller than the first threshold voltage.

Lighting device, head light and vehicle

A control circuit is configured to compare an input voltage measured through an input voltage detection circuit with a first threshold which is lower than a rated voltage of an external DC power supply and with a second threshold which is lower than the first threshold. The control circuit is configured, when detecting that a duration time in which the input voltage is kept lower than the first threshold reaches a predetermined holding period, to stop operating a switching device. The control circuit is configured, after detecting that the input voltage is lower than the second threshold, to more shorten a maximum ON time than that during a normal operation or lengthen an OFF time of the switching device than a maximum OFF time during the normal operation.

Power supply, head light device using the power supply, and vehicle using the headlight device

A microcomputer is configured to perform a first control and a second control. The first control is of: starting operation of a power converter, when a first power supply voltage exceeds a starting voltage; and stopping the operation of the power converter, when the first power supply voltage is below a maintaining voltage. The second control is of: switching off a second switching element, when a second power supply voltage exceeds a first threshold voltage; maintaining an off-state of the second switching element until the second power supply voltage is below a second threshold voltage; and switching on the second switching element, when the second power supply voltage is below the second threshold voltage.

Growing community of inventors

Osaka, Japan

Takahiro Fukui