Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Hiroyuki Asano

Masafumi Yamamoto

Masato Himeda

Daisuke Yamahara

Yuji Yoshimoto

Tetsuya Hamana

Takeshi Kamoi

Keisuke Seki

Katsunobu Hamamoto

Katunobu Hamamoto

Hisaya Takikita

Katsuyuki Doi

Satoshi Yagi

Koki Matsui

Hiroyuki Nakagawa

A lighting device includes: a first lighting control circuit; a second lighting control circuit which controls the first lighting control circuit; a first control power supply which supplies a first voltage to the first lighting control circuit; a second control power supply to which the first voltage is supplied and which supplies a second voltage to the second lighting control circuit; and a reset circuit which (i) when the reset circuit detects that the first voltage decreases to a first threshold or lower, causes the second control power supply to stop supply of the second voltage, and (ii) when the reset circuit detects that the first voltage increases to a second threshold or higher and that the second voltage is higher than a third threshold, causes the second control power supply to start supply of the second voltage after the second voltage decreases to the third threshold or lower.

Lighting device and luminaire

A DC power supply device includes a rectifier circuit, a conversion circuit and a control circuit. Conversion circuit includes a first capacitor, a first series circuit, a second series circuit, a third series circuit, a second diode and a Zener diode. First series circuit includes a first inductor and a switching element connected in series with each other. Second series circuit includes a second capacitor and a second inductor connected in series with each other. Third series circuit includes a first diode and a third capacitor connected in series with each other. First series circuit is electrically connected between both ends of first capacitor. Second series circuit is electrically connected in parallel with switching element. A cathode of Zener diode is connected with a connection point of first inductor and second capacitor. Zener diode has a Zener voltage larger than an output voltage of conversion circuit.

DC power supply device and lighting system using same

A lighting device includes a rectifier circuit, a conversion circuit, a constant current circuit and a control circuit. The conversion circuit includes a first series circuit, a second series circuit and a third series circuit. The conversion circuit is configured to output a DC current by on/off of a switching element being controlled by the control circuit. A high potential-side terminal of the third capacitor is electrically connected to an output terminal. The low potential-side terminal of the third capacitor is electrically connected to an output terminal, via the constant current circuit.

Lighting device and lighting fixture using same

A lighting device includes: a signal converting circuit which receives a dimming signal that is a rectangular voltage signal, and converts the dimming signal to a DC voltage signal corresponding to a duty ratio of the dimming signal; and a power supply circuit which receives an AC voltage and outputs DC current having a current value corresponding to the DC voltage signal. The signal converting circuit includes a resistor-capacitor (RC) circuit which integrates a signal corresponding to the dimming signal by way of charging and discharging to produce the DC voltage signal, and a time constant of the RC circuit during charging is greater than a time constant of the RC circuit during discharging.

A lighting device includes a rectifier circuit, a conversion circuit and a control circuit. A first inductor of a first series circuit and a second inductor of a second series circuit have inductances by which a time period, during which a diode is electrically conducted, is made shorter than a half period of a resonance period of a closed loop circuit. The closed loop circuit includes a first capacitor, the first inductor, a second capacitor and a third capacitor. The control circuit is configured to control a switching element in such a manner that the switching element is turned on at fixed periods.

A lighting device includes a voltage conversion circuit having at least a switching element connected to a positive potential side of the output terminals of the DC power source unit, and a drive unit which outputs a drive signal to the switching element. The drive unit has a first impedance element with a first impedance which is determined based on a power consumed by the drive unit before a predetermined time has elapsed after a control power source is supplied. A control capacitor for use in generating the drive signal is charged when the switching element is turned off during an on/off operation of the switching element. The lighting device further includes a second impedance element with a second impedance having a resistance component, which is arranged in a path in which the control capacitor can be charged in DC when the switching element does not perform the on/off operation.

Lighting device and illumination apparatus including same

An LED lighting device includes: a resistor Rconfigured to output a detection value of an inductor current Iflowing through an inductor Lduring an ON period of a switching element Q; a threshold generation sectionconfigured to generate a threshold value Vs of the inductor current Icorresponding to a dimming level; and a switching control sectionconfigured to control the switching element Qto turn on and off. The switching control sectionis configured to determine an OFF timing of the switching element Qbased on comparison between the detection value and the threshold value Vs of the inductor current I. The LED lighting device increases a period of a switching cycle of the switching element Qwith decrease of the dimming level.

LED lighting device and illuminating apparatus using the same

A power supply device comprises: a DC power supply section that outputs a DC voltage; a voltage conversion section that supplies a DC power to a load by ON/OFF drive of a switching element; a resistor; a control section that performs the ON/OFF drive of the switching element; and an auxiliary winding. The control section comprises: a calculation section that calculates a drive period of the switching element; a count section compares a calculation result obtained in the calculation section with an upper limit value of the drive period; and a flip-flop. When the calculation result is shorter than the upper limit value, the flip-flop sets the drive period, using the calculation result. When the calculation result is longer than the upper limit value, the flip-flop sets the drive period, using the upper limit value.

Power supply device and lighting device and lighting fixture using the same

An LED lighting device includes: a power source unit for supplying the DC output voltage to a light-emitting diode; a control unit for adjusting the DC output voltage; and a control power source unit for supplying a control power to the control unit. The control power source unit generates the control power with the DC output voltage and has: a current-limiting resistor for limiting an electric current that flows from the power source unit to the control unit; a constant voltage unit for converting a voltage to be applied to the control unit through the current-limiting resistor unit to a constant voltage; and a switching unit for switching a resistance value of the current-limiting resistor unit among a plurality of resistance values.

Lighting device and illumination apparatus using same

A control means has an adjustment function in a microprocessor to adjust variations in an output to a discharge lamp due to variations in components by correcting a duty ratio of a PWM signal for varying an operating frequency of an inverter circuit so that a detected value of a second detection circuit falls within a target range. The microprocessor switches paths to transmit the PWM signal between a path passing through a feedback circuit and a path passing through a voltage follower circuit by switches a switch circuit to supply the signal through the path passing through the voltage follower circuit in adjusting output variations in the preheating mode and the starting mode.

Electronic ballast with multimode lamp power control

An electronic ballast A includes an inverter circuit for converting a DC voltage into a high-frequency voltage, a resonant circuit which is connected between outputs of the inverter circuit and lights a discharge lamp at a high frequency by a resonant action, a dimming circuit for changing an output voltage to the discharge lamp by changing an operating frequency of the inverter circuit, a DC component detecting circuit for detecting a DC voltage component of the discharge lamp and a control operating circuit which detects an output signal of the DC component detecting circuit for every predetermined period to reduce or stop an output to the discharge lamp in the case where the output signal exceeds a predetermined reference value and to prohibit the protection operation when periodic change amount in the output signal reaches a predetermined value or higher.

Electronic ballast with lamp end of life detection and protection circuits

A electronic ballast includes an inverter circuit for converting a DC voltage into a high-frequency voltage, a resonant circuit connected between outputs of the inverter circuit so as to light a discharge lamp by a resonant action, a control circuit for controlling the inverter circuit, a dimming circuit for continuously changing an output voltage to the discharge lamp by changing an operation frequency in the inverter circuit, a DC component detection circuit and a voltage comparator for detecting whether or not the discharge lamp is at the end of the life at predetermined intervals and outputting an end of life detection signal upon detection of the end of the life state, and a frequency control circuit and a driving circuit for reducing or stopping an output to the discharge lamp by controlling switching elements in response to a life end detection signal inputted from the voltage comparator.

Growing community of inventors

Nara, Japan

Hiroyuki Asano