| 摘要 |
PROBLEM TO BE SOLVED: To stabilize driving of a switching element for bridge. SOLUTION: Each power source terminal Vcc of IC elements 43a, 43b is connected to the secondary side of a flyback transformer 29. A first power source circuit 96 comprising a resistance 95 and a Zener diode 97 is arranged on the secondary side of the flyback transformer 29, and applied voltage to the power source terminal Vcc becomes specified voltage V2 (15 V) generated with the first power source circuit 96. The IC elements 43a, 43b utilize secondary voltage (the lamp voltage) generated in the secondary winding 29b, and are controlled with an H bridge control circuit 11. Even if battery voltage dropped, driving voltage can be obtained from the secondary side of the flyback transformer 29, and MOS transistors 41a-41d are stably driven and controlled. |
