Hitachi, Ltd.

Mitsuo Akatsuka

Teruichi Tomura

Hiroyuki Iyama

Ichiro Imaizumi

Mineo Katsueda

Toshiaki Okada

A starter for a discharge lamp including first and second filaments, comprises an SCR having an anode and a cathode connected in series through the first and second filaments and a ballast transformer to an AC power supply. The gate electrode and the anode of the SCR are connected to each other through a first resistor, while the gate electrode is further connected through a second resistor to the power supply side.

Starter for discharge lamp

A voltage producing device comprises a circuit in which an AC power source, a coil and a first capacitor connected in series. A unidirectional triode semiconductor switching element is connected across both terminals of the capacitor, a voltage limiting semiconductor element is connected to a gate electrode of the switching element, and a charging-and-discharging circuit including a second capacitor is connected to a cathode of the switching element.

Discharge lamp control circuit

A solid state starter apparatus for a discharge lamp comprises a current limiter, an AC power supply, a discharge lamp of filament-preheating type and a switching circuit for controlling the turning on and off of the discharge lamp. The switching circuit further includes a lightedstate detector circuit for detecting the turning on or off of the discharge lamp, a current breaker circuit controlled by the lighted-state detector circuit to cause the filament current to be turned on and off, and a preheater circuit for starting to supply a filament preheating current in accordance with the magnitude of the current controlled by the current breaker circuit.

Solid state starter apparatus for a discharge lamp

An electric discharge lamp lighting circuit in which a discharge lamp is lighted by a circuit comprising a semiconductor switching circuit in which the cathode of a first thyristor is connected to the gate of a second thyristor and the first and second thyristors are commonly connected at the respective anodes, an integration circuit consisting of a capacitor and a resistor and connected between the gate of the first thyristor and the cathode of the second thyristor, a resistor connected between the integration circuit and the anode of the first thyristor, and a resistor connected between the gate and cathode of the second thyristor.

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Tokyo, Japan

Mitsuo Akatsuka