JPH0322397U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing the configuration of a conventional lighting device. 1... AC power supply, 2... Rectifier, 3... Inverter circuit, 4... Discharge lamp, 5... Switch circuit,
6... Switch control circuit, Th... Thyristor as a switching means, C2... Capacitor as a time element, R3... Resistor as a time element, R
5, R6...Resistor forming a voltage dividing circuit.

Claims (1)

[Claims for Utility Model Registration] (1) An inverter circuit equipped with a rectifier that rectifies the output of an AC power supply, an output transformer that converts the output of the rectifier into a high-frequency voltage, and a secondary side of the output transformer of the inverter circuit. A switch circuit is provided between one end of the provided high voltage output winding and one electrode of the discharge lamp, and a switch element of the switch circuit is activated when a certain time period elapses from the time when the AC power source is turned on. A discharge lamp lighting device comprising a closing switch control circuit, wherein the output voltage of the high voltage output winding is applied to the discharge lamp through the switch circuit, an impedance element being connected in parallel to the discharge lamp, and an impedance element being connected in parallel to the discharge lamp; The control circuit comprises a circuit that performs a timed operation based on the voltage across the switch element and provides a trigger signal to the switch element when a predetermined time period has elapsed since the voltage appeared across the switch element. A discharge lamp lighting device characterized by: (2) The switch control circuit includes a voltage reduction circuit that reduces the voltage across the switch element, and a capacitor that is charged by the output of the voltage reduction circuit via a current limiting element. 2. The discharge lamp lighting device according to claim 1, further comprising a circuit that provides a trigger signal to said switch element when a voltage reaches a predetermined value. (3) The discharge lamp lighting device according to claim 1 or 2, wherein the impedance of the impedance element is set lower than the impedance of the discharge lamp when the discharge lamp is at low temperature and low humidity. (4) The discharge lamp lighting device according to any one of claims 1 to 3, wherein the impedance element is a capacitor or a reactor. (5) The switch circuit includes a thyristor as the switch element and a diode bridge rectifier circuit in which four diodes are bridge-connected, and a pair of AC input terminals of the diode bridge rectifier circuit are connected to the high voltage output winding. 2. The thyristor is connected to one end of the wire and to one end of one electrode of the discharge lamp, respectively, and the anode and cathode of the thyristor are connected to the positive DC output terminal and the negative DC output terminal of the diode bridge rectifier circuit, respectively. 5. The discharge lamp lighting device according to any one of 1 to 4.