Matsushita Electric Works, Ltd.

Naoki Ohnishi

Shigeru Ido

Tomoyuki Nakano

Masahiro Naruo

Takashi Kanda

Masahito Ohnishi

Yoshinobu Murakami

Tokushi Yamauchi

Tomoaki Mannami

Kazuo Yoshida

Kei Mitsuyasu

Akio Okude

Katsuyuki Kiyozumi

Yoshifumi Kuroki

A discharge lamp lighting device includes a high frequency power supply for supplying high frequency power to the discharge lamp via a first impedance element, a DC power supply for applying DC voltage to the discharge lamp via a second impedance element, a dimming control circuit for carrying out a dimming of the discharge lamp by controlling the power supplied to the discharge lamp, a DC voltage detection circuit for detecting a DC component of the voltage applied to the discharge lamp, and an output correction unit for making a correction to the power supplied to the discharge lamp in accordance with a value detected by the DC voltage detection circuit. It can light the discharge lamp stably regardless of a variation in temperature.

Dimmable discharge lamp lighting device

A power converter apparatus in which a switched capacitor circuit includes one or more sets of cells connected in series each having a capacitor as a voltage supply source and a bridge circuit for inverting the polarities of the capacitor, the switched capacitor circuit is connected to a load, there is provided a means for parallelly charging the capacitors of the cells with a D.C. voltage source, any number of the cell capacitors are connected in series with any polarity to control supply of an A.C. output to the load. Whereby the power converter apparatus using the switched capacitor circuit can supply A.C. power with less distortion to the load without increasing the withstand voltage of the switching elements and without any need for provision of large inductors or capacitors.

Power converter apparatus for a discharge lamp

A discharge lamp lighting device has first switching means for converting AC power into DC power and second switching means for converting the DC power into a high frequency power, the first switching means being driven subsequently to a driving of the second switching means, and the device is arranged for intermittently applying a pulse voltage to a discharge lamp during its dimming lighting, whereby any secondary voltage can be effectively lowered and any flash apt to occur during the dimming lighting can be restrained.

Discharge lamp lighting device

Growing community of inventors

Kadoma, Japan

Naoki Ohnishi