DISCHARGE LAMP LIGHTING DEVICE, LIGHTING DEVICE FOR DISCHARGE LAMP, AND LIGHTING SYSTEM

摘要

PURPOSE: To make possible preventing thermal damage to electronic parts by providing a second thermal protector which cuts off currents to the electronic parts and is mounted in a position in which it can detect the heating of the electronic parts. CONSTITUTION: A second thermal protector 12 such as a thermal fuse is mounted inside a case 4 near a pulse generating circuit 9 to detect abnormal rises in temperature of electronic parts constituting the circuit 9. The protector 12 is inserted in series between one of the extension lines 8 of the coil of a ballast main body 1 and a commercial AC power supply. The protector cuts off power on detecting abnormal rises in temperature of the electronic parts constituting the circuit 9, thereby cutting off currents to the electronic parts. Even if the temperature inside the case 4 is raised excessively by the influence of direct sunlight before the temperature of the coil 3 of the ballast rises, the protector 12 detects this temperature rise and can protect the electronic parts, so that thermal damage to the electronic parts can also be prevented.