| 摘要 |
PURPOSE:To reduce the number of parts and to simplify the constitution of a circuit by equipping the title device with a monitoring circuit which temporarily stops the oscillation of DC-DC converters in response to increase in the output voltage of a boosting transformer. CONSTITUTION:When a main discharge capacitor 32 is charged to a specified voltage value, the monitoring circuit (an oscillation stopping circuit) operates responding to the increase in the output voltage of the boosting transformer 21 and temporarily stops the oscillation of the DC-DC converters 21-24. Since the output voltage of the boosting transformer 21 is of an alternating type, the monitoring circuit is reset in a condition permitting the oscillation immediately after the temporary stop of operation. Although the DC-DC converters start oscillating again, the monitoring circuit operates to stop the oscillation immediately after re-oscillation is started, as far as the main discharge capacitor 32 is charged to the specified value. As a result, a display capacitor 27 repeats charging and discharging, and a display member turns on and off a light alternately. By this means, the number of the parts can be reduced, thereby simplifying the circuit of this device. |
