Matsushita Electric Works, Ltd.

Panasonic Corporation

Panasonic Electric Works Co., Ltd.

Toshiba Lighting & Technology Corporation

Panasonic Intellectual Property Management Co., Ltd.

Hiroyuki Sako

Hiroshi Kubota

Akinori Hiramatsu

Kazuhiro Gotoh

Takeshi Saito

Shigeaki Yamasaki

Hiroki Nakagawa

Hiroshi Terasaka

Katsunobu Hamamoto

Nobukazu Miki

Shigeaki Yamazaki

Hiroshi Kido

Koji Yamada

Masahiko Kamata

Naoko Iwai

Tokushi Yamauchi

Masahiro Yamanaka

Yukio Yamanaka

Koji Nishiura

Futoshi Okamoto

Atsushi Ueoka

Seiji Soga

Naokage Kishimoto

A dedicated power source for LED lamps capable of reliably detecting attachment of an LED lamp is provided. A dedicated power source has a DC power source portion, and includes a lighting circuit which receives power supplied from the DC power source portion and light-controls an LED lamp including an LED element and a detection resistor connected in parallel to the LED element and an attachment detecting portion for detecting attachment of the LED lamp based on a voltage level changing in accordance with attachment/detachment of the detection resistor by attachment/detachment of the LED lamp.

Power source unit for LED lamps, and LED lamp system

The LED lighting device includes a lighting circuit unit, a current detecting unit, a voltage detecting unit, and a control unit. The lighting circuit unit is adapted in use to be connected to a lamp socket to be connected to a LED lamp, and is configured to provide an output voltage in the form of a DC voltage to the lamp socket in a manner to turn on the LED lamp. The current detecting unit is configured to detect an output current which is caused by the output voltage and is supplied from said lighting circuit unit to said lamp socket. The voltage detecting unit is configured to detect the output voltage of said lighting circuit unit. The control unit configured to control the lighting circuit unit. The control unit is configured to perform constant-current control of control the lighting circuit unit in a manner to regulate the output voltage such that the output current is identical to a target value while keeping the output voltage not higher than a maximum-load voltage, when the output current detected by the current detecting unit is not less than a predetermined threshold value, and is configured to perform no-load control of controlling the lighting circuit unit in a manner to regulate the output voltage such that the output voltage is kept identical to a no-load voltage higher than the maximum-load voltage, when the output current detected by the current detecting unit is less than the predetermined threshold value.

LED lighting device

An LED dimming includes: current adjusting means (constant current circuit) for variably controlling a magnitude of a current flowing through an LED load; switching means (transistor) for intermittently controlling the current flowing through the LED load; and dimming controlling means (microcomputer) for controlling the current adjusting means and the switching means upon receiving a dimming signal outputted from a dimmer. In a case where the dimming signal outputted from the dimmer is on a higher brightness side than a predetermined level, the dimming controlling means flows a continuous current though the LED load, and dims the LED load based on a magnitude of the flowing current, and in a case where the dimming signal outputted from the dimmer is on a lower brightness side than the predetermined level, the dimming controlling means flows a pulse current through the LED load, and changes a mean value of waveforms of the pulse current, thereby dims the LED load. In this LED dimming apparatus, noise is less likely to occur even in a case where such an LED current is large, and brightness is less likely to vary even in a case where a dimming degree is increased.

LED dimming apparatus

A LED illuminating device includes: a power source device, a controller, an LED lighting device, and an LED unitincorporating LEDs of a plurality of emission colors. The device is configured to mix the lights of the LEDs at an arbitrary proportion and set the lights in an arbitrary color mixture proportion on the basis of a dimming signal from the controller. The device is further configured so that: a coefficient specific to the LED unit at which an emission color of the LED unit becomes a desired color can be set to a signal value of the controller preliminarily set as a standard. The LED lighting device can control an emission amount of the LEDs having the respective emission colors by using a value calculated by a calculation expression employing the specific coefficient.

LED illuminating device

An electronic track lighting system comprises a power supply filter circuit having an input connected to an alternating current power supply AC, a rectifier circuit connected to an output of the power supply filter circuit, an inverter circuit connected to an output of the rectifier circuit and outputting a high frequency voltage by on/off operation of switching elements therein, a lamp load, and a power track providing supply voltage to the lamp load. The lighting system further comprises a first unit which is interposed between the AC power supply and an input of the power track and includes at least the power supply filter circuit, and a second unit which is provided as a structure independent from the first unit, is connected to the power track and outputs a high frequency voltage to the lamp load.

Electronic track lighting system

A power supply device in which an inverter circuit is supplied with power directly from a rectification circuit, the inverter circuit has a pair of switching elements connected in series with each other and connected between both ends of the rectification circuit through an impedance element, a series circuit of the impedance element, two capacitors and an inductor is connected in parallel to one of the switching elements of the inverter circuit connected to positive polarity one of the both ends of the rectification circuit, a load is connected across one of the capacitor, a valley filling circuit receives an output of the inverter circuit through a diode provided in the valley filling circuit and supplies it to a power supply capacitor provided therein and, when a DC output voltage of the rectification circuit drops, the valley filling circuit supplies power to the inverter circuit via the power supply capacitor and another diode provided therein. Thereby, fluctuations in a current supplied to the load can be effectively reduced.

Power supply device

A power source device for supplying a high frequency AC voltage to a load. An source voltage is changed by a rectifier into a into a DC voltage that is supplied to an inverter to produce the high frequency AC voltage. The high frequency AC voltage is fed back to the rectifier where a resonant circuit resonates with the high frequency AC voltage. The inverter may be self-excited through feedback of the high frequency AC voltage. In this power source device, any pausing in the AC source voltage is filled in through the feedback and resonant circuits.

Power source device

An electronic ballast for hot cathode discharge lamp comprises a DC voltage source, a chopper, and an inverter. The chopper includes a switching element connected in series with an inductor across the DC voltage and driven to turn on and off for providing a periodically interrupted voltage which is smoothed by a capacitor to produce a smoothed DC voltage as a chopper output. The inverter includes at least one switching element which is coupled to the chopper output to produce therefrom a high frequency AC voltage as an inverter output to be applied to cathodes of the discharge lamp for lighting the discharge lamp. The ballast is characterized to include an inverter controller and a delay circuit. The inverter controller controls the inverter to operate selectively in a normal mode of providing the inverter output of a first level and in a limited mode of providing the inverter output of a second level which is lower than the first level and is determined to give a preheating current to the cathodes. The delay circuit delays the start-up of the inverter for a time period from the start-up of the chopper. The inverter controller controls the inverter to operate in the limited mode after the start-up of the inverter for a predetermined period for preheating the discharge lamp after which the inverter controller allows the inverter to operate in the normal operation mode for lighting the discharge lamp.

Electronic ballast for hot cathode discharge lamps

A power supply for driving one or more loads includes a DC voltage source, an inverter connected to the DC voltage source for providing a high frequency AC voltage at its output end, and an output transformer having a primary winding and a secondary winding. The primary winding is coupled to the output end of the inverter through a tuning inductor, while the secondary winding is coupled to the load. A tuning capacitor, which constitutes a resonant circuit in cooperation with the resonance inductance for supplying a resonance current to the load, is connected across the secondary winding of the output transformer in parallel relation to the load. The tuning capacitor is arranged in circuit on the opposite side of the secondary winding from the load such that the tuning capacitor is open-circuited when the load is disconnected from the secondary winding.

Power supply

A power supply with an inverter capable of avoiding the inverter from producing excessive high voltage when a load is detached or the load impedance is greatly increased. The inverter is energized by a fixed DC voltage source and includes at least one switching element and an L-C resonant circuit. The switching element is driven to turn on and off and cooperative with the L-C resonant circuit to produce a high frequency AC voltage at an inverter output for driving a load. The inverter includes first and second clamping diodes connected in series across the DC voltage source in anti-parallel relation thereto with the first and second diodes defining therebetween a first connection point. Also included in the inverter is a pair of first and second impedance elements which are connected in series across the inverter output to provide a divided voltage indicative of an output voltage of the inverter with the first and second impedance elements defining therebetween a second connection point. The first and second connection points are connected to each other so as to keep the points at a voltage level nearly equal to a fixed voltage of the DC voltage source, in such a manner as to limit the output voltage of the inverter below a predetermined level by allowing a clamping current to flow through the first and second diodes and impedance elements and through the DC voltage source to escape the excessive voltage developed in response to the increase in the impedance of the load.

Inverter power supply

An inverter device has a full-wave rectifier providing a pulsating DC voltage from an input AC voltage, a smoothing circuit. The smoothing circuit includes a choke coil, a smoothing capacitor and a switching element chopping the pulsating DC voltage through the choke coil into a smoothed DC voltage at the smoothing capacitor. An inverter is included to have the element common to the smoothing circuit and operating to switch the smoothed DC voltage to apply a resulting voltage to a load circuit including a load, inductance and capacitor. The inductance and capacitor define an oscillation circuit providing to the load an oscillating current composed of first and second currents of opposite directions. The oscillating current alternating to flow for a nominal on-time duration determined by a circuit constant of the oscillation circuit itself. A controller is included to detect the termination of the second current and excites the common switching element at a timing dependent upon the termination of the second current so as to start flowing the first current. The controller includes a timer for separately controlling an actual on-time duration for flowing the first current within the nominal on-time duration, whereby enabling to regulate the accumulated DC voltage in the smoothing capacitor at a desired level by controlling to vary the actual on-time duration of the common switching element.

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Hirakata, Japan

Hiroyuki Sako