| 摘要 |
PURPOSE:To provide stable high pulse voltages so as to extend the life of a high pressure vapor discharge lamp by installing in a lamp external bulb a lamp starting circuit comprising a pyro-current bypass resistance connected in parallel to a nonlinear ceramics condensor. CONSTITUTION:A high pressure vapor discharge lamp comprises a series circuit of a thermal switch 114 and a nonlinear ceramics condensor (FEC) 116 connected in parallel to a light-emitting tube 112 and serving as a starter, and a pyro- current bypass resistance R122 connected in parallel to the FEC 116. Each of the elements is installed inside an external bulb 120. Because the thermal switch 114 is on at the start of the lamp, a voltage is applied to the FEC 116 and the FEC 116 generates a pulse. After the FEC 116 is polarized, the thermal switch 114 is off. As temperature is further raised, the maximum pyro-current is by passed via the pyro-current bypass resistance R122 and the FEC 116 is completely depolarized. |
