| 摘要 |
<p>PURPOSE:To prevent the 1st switching element connected in series to a discharge tube from going out of order permanently in the event of failure in commutation by providing a diode between the cathode of a discharge lamp and the commutation capacitor of an automatic strobe of series control type. CONSTITUTION:When a discharge lamp 3 and the 1st switching element 5 are triggered by trigger circuits 4, 6, the discharge lamp fluorescences by the discharging of the discharge energy of a main capacitor 1. Upon arriving of the quantity of the light reflected by an object at a prescribed value, the 2nd switching element 10 is conducted by the signal from a photodetecting circuit 11, and turn-off current flows from a commutation capacitor 9 to the 1st switching element. If there is no diode 14 in the event of failure in turn-off, the charged of the commutation capacitor charged to reverse polarity flows to the 1st switching element and this associates the possibility of its permanent trouble, but if there exists the diode, the greater part of the charged charge is consumed by a resistance 15.</p> |
