Abstract: An ignition apparatus is provided with a Zener diode as a limiter device, which limits a primary voltage of an ignition coil to be less than a Zener voltage, and a switching circuit, which prohibits a limiter function of the Zener diode at a start of discharge and switches the limiter device to perform the limiter function for a predetermined time period following the start of discharge. A secondary voltage is limited to be more than a secondary limit value. Even when blowout arises in discharging, re-discharging is avoided from arising immediately after the blowout and exhaustion of a spark plug caused by repetition of discharging is avoided.

Abstract: An ignition system is provided, which can restrict decreasing of constant-voltage duration of a spark plug and effectively prevents the occurrence of an accidental fire in an engine. A typical ignition system includes a secondary coil having one end connected to a positive side of a battery via a low-voltage side path and the other end connected to a center electrode via a connecting path which connects the secondary coil and the spark plug. A constant-voltage path having a grounded end is connected to the connecting path. A block diode is arranged between the secondary coil and a point where the constant-voltage path is connected with the connecting path. A Zener diode is disposed within the constant-voltage path. Each anode of the block diode and the Zener diode is mutually connected.

Abstract: The plasma ignition device includes an ignition plug, a breakdown discharge circuit configured to apply a high voltage to the ignition plug to cause a breakdown discharge in a discharge space in the ignition plug, and a plasma discharge circuit configured to accumulate electric energy supplied from a power supply and applies the accumulated electric energy to the ignition plug as a current to bring a gas in the discharge space into a plasma state so that the gas in the plasma state is injected to a combustion chamber of an combustion engine during the breakdown discharge in order to cause ignition. The plasma discharge circuit includes an energy accumulating section, and an energy supplying section configured to supply the electric energy to the energy accumulating section during a short time period immediately before the breakdown discharge circuit applies the first voltage to the ignition plug.

Abstract: The plasma ignition device includes an ignition plug, a breakdown discharge circuit configured to apply a high voltage to the ignition plug to cause a breakdown discharge in a discharge space in the ignition plug, and a plasma discharge circuit configured to accumulate electric energy supplied from a power supply and applies the accumulated electric energy to the ignition plug as a current to bring a gas in the discharge space into a plasma state so that the gas in the plasma state is injected to a combustion chamber of an combustion engine during the breakdown discharge in order to cause ignition. The plasma discharge circuit includes an energy accumulating section, and an energy supplying section configured to supply the electric energy to the energy accumulating section during a short time period immediately before the breakdown discharge circuit applies the first voltage to the ignition plug.

Abstract: A head lamp device for a vehicle includes a DC power source, a diode array having a plurality of series-connected light emitting diodes and a current control circuit that supplies driving current to the diode array. The current control circuit is constituted of a current supply circuit, a voltage measuring circuit, a comparing circuit that compares the voltage drop with a reference value, a judging circuit for judging that there is a short-circuiting at any of the light emitting diodes based on the comparison by the comparing circuit, and a display unit for displaying an alarm when the judging circuit judges that there is a short-circuiting.

Abstract: A LED-based lamp apparatus includes a LED unit having multiple LEDs connected in series, a step-up circuit for stepping up a power supply voltage by a switching action of a switching element to supply an electric current to the LED unit, a sensing element for measuring a value of the current, and a controlling element connected in series with the LED unit to control the current based on the measured current value. When some of the LEDs of the LED unit are broken and short-circuited due to, for example, long-term use, the current increases instantaneously and an overcurrent condition occurs. In this case, the controlling element limits the current immediately to correct the overcurrent condition. Thus, the controlling element prevents the overcurrent condition from causing a secondary failure to normal LEDs of the LED unit.

Abstract: A LED-based lamp apparatus includes a LED unit having multiple LEDs connected in series, a step-up circuit for stepping up a power supply voltage by a switching action of a switching element to supply an electric current to the LED unit, a sensing element for measuring a value of the current, and a controlling element connected in series with the LED unit to control the current based on the measured current value. When some of the LEDs of the LED unit are broken and short-circuited due to, for example, long-term use, the current increases instantaneously and an overcurrent condition occurs. In this case, the controlling element limits the current immediately to correct the overcurrent condition. Thus, the controlling element prevents the overcurrent condition from causing a secondary failure to normal LEDs of the LED unit.

Abstract: A head lamp device for a vehicle includes a DC power source, a diode array having a plurality of series-connected light emitting diodes and a current control circuit that supplies driving current to the diode array. The current control circuit is constituted of a current supply circuit, a voltage measuring circuit, a comparing circuit that compares the voltage drop with a reference value, a judging circuit for judging that there is a short-circuiting at any of the light emitting diodes based on the comparison by the comparing circuit, and a display unit for displaying an alarm when the judging circuit judges that there is a short-circuiting.

Abstract: A hybrid IC of electronic circuit for a discharge lamp is disposed on the bottom of a metal case. A transformer, an inductor, a transformer, and a capacitor are disposed in a resin case. The resin case is contained in a metal case. In this instance, the transformer, the inductor, the transformer, and the capacitor are located outside the outer periphery of the IC so that the IC does not overlap on the transformer and other components. The transformer for a starter circuit has a secondary winding the inductance of which is 2.5 mH or larger, and a capacitance of a smoothing capacitor of a DC—DC converter is 0.5 &mgr;F or smaller. The switching frequency f of a MOS transistor is selected so that L2×C1 is equal to or larger than 1×10−1×f−1.68.

Abstract: A charging and discharging integration circuit packed in an IC package is disclosed. A charging current is transferred from a constant voltage source to a capacitor element through a first external terminal and a charging resistor placed outside the IC package. The capacitor element is grounded. A driving current is transferred from the constant voltage source to a current limit driving circuit through a discharging resistor placed outside the IC package through first and second external terminals. A discharging current composed of the charging current and a capacitor current flowing from the capacitor element passes a current limiting circuit through a third external terminal. The driving and discharging current are discharged to the earth through a fourth external terminal.