| 摘要 |
PURPOSE: To provide a starting circuit which is actuated by a main RF power source and does not require another additional power source to start arc discharge in an electrodless HID lamp with a starting signal applied to a starting electrode. CONSTITUTION: A starting circuit 14 supplies a starting voltage to a fixed or movable starting probe 12 at the almost same time as a voltage is applied from a main power source to an exciting coil 18. The starting circuit 14 supplies a starting signal to a gas probe starting device containing a fixed starting electrode 30 combined to a small chamber 32 which is fixed to outside wall of an arc tube 16 and contains relatively low pressure gas. By a resonance action of the starting circuit 14, a sufficiently high voltage is applied and glow arcing is ignited in a low voltage starting chamber 32. Successively, capacitive coupling of the starting voltage ionizes the filling, and arc discharge is started in it. An additional circuit is provided so that after arc discharge started, glow discharge is reliably extinguished. |
