| 摘要 |
<p>PURPOSE:To obtain the quantity of light emission with a desired level by varying a charging current to an integrating capacitor according to the changing voltage of a main capacitor. CONSTITUTION:An integrating capacitor C4 starts charging in relation to the start to light emission of a flash discharge tube X1 and a charging current generating circuit supplies the charging current to the capacitor C4. A dimming signal generating circuit outputs a dimming signal when the charging voltage of the capacitor C4 attains to a specific value and a dimming circuit receives the signal and stops the light emission of the discharge tube X1. A charging current correcting means Q5 detects the charging voltage of a main capacitor C1 and varies the charging current of the capacitor C4 according to the detected voltage to obtain the desired quantity of light emission of the discharge tube X1 all the time.</p> |
