| 摘要 |
PURPOSE:To prevent the ultra-high pulse voltage from being continuously generated for a long period by resetting the memory content of a memory means when an AC power source is normal and non-lighting state continues after the ultra-high pulse voltage is applied. CONSTITUTION:When an AC power source V1 is normal and a high-pressure discharge lamp DL is turned on, if an accident such as the breakage of a light emitting tube occurs, the voltage nearly equal to the voltage of the AC power source V1 appears across both input terminals of an instant restarter IC immediately after the high-pressure discharge lamp DL is turned off, and a capacitor C5 starts to be charged by this voltage. When the voltage across the capacitor C5 reaches the break-over voltage of a voltage response switch element Q4 in a relatively short period T1, the voltage response switch element Q4 is turned on, voltage is induced on the primary winding of a transformer TF2, and a transistor Q5 is turned on by the voltage generated on the secondary winding of the transformer TF2. When the transistor Q5 is turned on, charges of a capacitor C4 serving as a memory means are discharged in a short time, it functions as a reset means, and a transistor Q3 is turned off. The ultra-high pulse voltage generation period can be limited to about 1-5sec at the longest. |
