| 摘要 |
PURPOSE:To prevent continuous electric discharge after flash discharge, by providing a charge control circuit and operating an electric power source switch. CONSTITUTION:When a charge start operation switch 16 is closed, a power switch 6 is closed when the charged voltage is low to charge, and when the charged voltage in a discharge capacitor 8 reaches a specified value, the output voltage of a capacitor voltage detecting circuit 9 becomes larger than the output voltage of a charge completion reference voltage generating circuit 13. As a result, a charge completion voltage comparator 12 operates to open the switch 6 through an AND gate 15. A trigger pulse is applied from a trigger pulse generating circuit 11 to a flash discharge tube 10, and the electric charge in the capacitor 8 is applied to the discharge tube 10 discharge a flash. As a result of this discharge, when the voltage in the capacitor 8 declines below a specified value, a charge break timer circuit 14 issues a signal to open the switch 6 for specified time through the gate 15. When the charge break signal stops after elapse of specified time, the switch 6 is closed to start charging into the capacitor 8. By this charge pause for specified time, the residual ions in the discharge tube 10 are extinguished, so that continuous discharge may be prevented. |
