Panasonic Intellectual Property Management Co., Ltd.

Matsushita Electric Works, Ltd.

Yoshikazu Kado

Koji Watanabe

Kazuhiro Kumada

Satoru Nagata

Yukio Yamanaka

Nobukazu Miki

Tadahiro Kono

Toshihiro Nishida

Kazuhiro Nishimoto

A lighting device includes an electricity storage electrically connected in parallel with a solid light source, a switching circuit that produces a current to supply the current to the electricity storage, and a control circuit that controls, according to a dimming level, burst dimming by controlling the switching circuit so that the solid light source is lit intermittently. When the dimming level is a threshold level or more, the control circuit sets an electricity storage capacity of the electricity storage to a first capacity, and sets a frequency by the burst dimming to a first frequency. When the dimming level is below the threshold level, the control circuit sets the electricity storage capacity to a second capacity smaller than the first capacity, and sets the frequency by the burst dimming to a second frequency higher than the first frequency.

Lighting device, lighting fixture and lighting system

The LED lighting device of the present invention includes: a power supply circuit connected between a light source including a light emitting diode and a power source and including a series circuit of a switching device and an inductor; an inductor current detector configured to provide a measurement value indicative of an inductor current flowing through the inductor; a drive circuit configured to turn on the switching device at a predetermined period and turn off the switching device when the measurement value is equal to a first threshold or more; a load current detector configured to measure a load current flowing through the light source; and a protection device configured to, when the load current measured is equal to a second threshold or more, perform a protection operation of changing, to reduce the load current, a circuit constant of a power supply path in which the load current flows.

LED lighting device

An electronic ballast for a discharge lamp has a compact arrangement of electric parts. The ballast includes an AC-DC converter and an inverter giving a high frequency output voltage for operating the lamp. The inverter includes switching elements, a control circuit, and an output transformer for connection with the lamp. A single circuit board mounts the electric parts forming the converter and the inverter. The circuit board is accommodated within a tubular casing together with a dielectric sheet which is provided for insulating the circuit board as well as the electric parts from the casing. The output transformer is mounted on a top surface of the circuit board together with some of the other electric parts. The ballast includes chip components forming a detection circuit for lamp condition, and the circuit board mounts the chip components on a bottom surface at a location immediately opposite of the output transformer.

Electronic ballast for a discharge lamp

Growing community of inventors

Osaka, Japan

Yoshikazu Kado