POWER UNIT, STROBOSCOPIC DEVICE HAVING THE SAME, AND IMAGE PICKUP DEVICE INCORPORATING THE STROBOSCOPIC DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of excessively large currents by providing a current limiting means which controls the charged state of a capacitor on the secondary side of a step-up transformer, by using the boosted output of the transformer impressed through a switching element that controls turning on/off operations based on the pulse output from the primary side of the transformer. SOLUTION: A stroboscopic device is constituted to contain a power unit DX for a separately excited boosting circuit SX, a main capacitor 7 for power supply and a discharge tube 8 which is connected to both ends of the capacitor 7 and emits light by consuming the charges in the capacitor 7 when a trigger circuit is actuated. A current limiting means 12 is constituted of resistors 13 and 14 which are connected in series between the secondary winding 10B of a step-up transformer 10 and the capacitor 7 and a capacitor 17 which is connected between the base and emitter of a transistor 16 and forms a delay circuit together with a resistor 15. When a control circuit 11 starts to operate and a rectangular-wave pulse signal is supplied to the control electrode of a switching element 9 in a prescribed cycle, the element 9 starts turning on/off operations based on the cycle of the pulse signal. The capacitor 7 is charged from the secondary winding 10B of the transformer 10 through a rectifier diode 6.