| 摘要 |
PROBLEM TO BE SOLVED: To balance a tube current by the stable operation of a balance coil even when a cold cathode tube has a small diameter and a high equivalent resistance value. SOLUTION: The tube current balancing circuit comprises a plurality of discharge tubes as a load of an inverter circuit 10, and a balance coil 14 levelling the tube current of the discharge tubes. Here, the discharge tubes are cold cathode tubes 12 having equivalent resistance value of 50 kΩor higher when a current is flowing. The balance coil is composed of two windings having same turns with each other, and a self resonance frequency of the balance coil is set high so as to become not less than 1.5 times the operation frequency of an inverter transformer of the inverter circuit. COPYRIGHT: (C)2006,JPO&NCIPI |
