| 摘要 |
PURPOSE:To make it easy to design at low cost without needing large-sized parts with large withstand voltage or great contrivance in design to make enough voltage. CONSTITUTION:This is provided with an inverter circuit 3, which supplies a lamp 1 with high frequency power, and preheating circuits 21 and 22, which supply filaments f1 and f2 with preheating currents If1 and If2. The voltage supplied from the inverter circuit 3 to the lamp 1 is nearly confined to the startable voltage in the vicinities of the objective preheating currents If1 and If2. After it reaches the set voltage, the preheating circuits 21 and 22 increase the preheating currents If1 and If2 gradually, and at some time the voltage VL tops the lamp startable voltage, and the lamp 1 starts. |
