Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Denson Corporation

Yukio Kunieda

Noboru Yamamoto

Tetsuya Miwa

Isao Goto

Tomoyuki Funayama

An electric discharge lamp device has a lighting start voltage storage circuit for storing a lamp voltage immediately after the start of lighting of a lamp, and a change detection circuit for detecting a change in the lamp voltage by subtracting the lamp voltage immediately after the start of lighting of the lamp from the lamp voltage detected currently. The electric power supplied to the lamp is controlled based upon the change in the lamp voltage.

Electric discharge lamp device

A method for controlling a discharge lamp by a power controlling device on an automobile vehicle includes a starting step and a switching step. The device supplies electricity to the lamp. In the starting step, the discharge lamp starts to emit a light such that the device supplies a first electricity. In the switching step, the device switches from the first electricity to a second electricity so that the lamp maintains to emit the light with the second electricity, which is smaller than the first electricity. In the switching step, a temperature of the lamp is decreased with a temperature gradient, which is equal to or smaller than a predetermined gradient.

Control method for discharge lamp

The discharge lamp lighting apparatus includes a high-voltage generating coil connected in series to a discharge lamp for applying a high voltage to the discharge lamp to turn on the lamp, an inverter for inverting a dc voltage into an ac voltage in order to supply a lamp current to the discharge lamp on an alternating basis through the high voltage generating coil, a lamp voltage detecting circuit for detecting a voltage across the discharge lamp as a lamp voltage, and a lamp power control circuit for controlling an ac power supplied to the discharge lamp from the inverter on the basis of the lamp voltage detected by the lamp voltage detecting circuit. The lamp voltage detecting circuit detects the lamp voltage by subtracting a voltage in proportion to a sum of voltage drops across devices lying on a current path over which the lamp current flows other than the discharge lamp from a voltage in proportion to the dc voltage.

Discharge lamp lighting apparatus

An ignition system includes an ignition coil which provides ignition voltage of one polarity, an igniter which supplies the primary current to the ignition coil at regular timings and a zener diode connected in series with the primary coil of the ignition coil. The zener diode shares a constant voltage drop of the opposite polarity at the secondary coil of the ignition coil, thereby reducing troublesome voltage induced in said secondary coil other than at regular ignition timings. On the other hand, the zener diode does not share the voltage drop of the ignition voltage at the regular timings, and thus no energy loss is incurred.

Ignition system having ignition coil

An ignition system includes an ignition coil which provides ignition voltage of one polarity, an igniter which supplies the primary current to the ignition coil at regular timings and a zener diode connected in series with the primary coil of the ignition coil. The zener diode shares a constant voltage drop of the opposite polarity at the secondary coil of the ignition coil, thereby reducing troublesome voltage induced in the secondary coil other than at regular ignition timings. On the other hand, the zener diode does not share the voltage drop of the ignition voltage at the regular timings, and thus no energy loss is incurred.

Growing community of inventors

Nagoya, Japan

Yukio Kunieda