Stroboskopeinrichtung

摘要

A strobe lamp fixture 50 is operable from any AC supply voltage 18 in a range of 90 to 255 volts and is controlled by a CPU 62 which provides firing signal to an SCR unit 58, a boost gating circuit 72 and a trigger circuit 64. The trigger circuit 64 starts the lamp 41 which is initially supplied from a boost capacitor 70 via gate 72 and then from the mains AC 18 via SCR's 58. A 400 volt supply for capacitor 70 and for trigger circuit 64 is formed by a regulator 60 in which a voltage multiplier is fed via SCR's (113, Fig. 4), the phase angle of which is controlled to regulate the 400 volt output. The CPU 62 determines the current AC input voltage from the triggering delay of the SCR's in regulator 60 and determines the frequency from the time between zero crossings sensed by a detector 56. The CPU 62 can then determine the necessary conduction angle for the SCR's 58 to achieve a desired lamp intensity with the current supply voltage and frequency. The CPU 62 is AC coupled to circuits 58, 64, 72 via one shots 141, 143 which have a duration of 100 microseconds so that the boost capacitor 70 can recharge while lamp 41 is firing through SCR's 58, and so that the lamp cannot go into a runaway firing if one of the firing signals from CPU 62 should over become stuck in the firing position. A plurality of strobe fixtures 50 may be connected to a central controller (12, Fig. 1) via a serial link 16. According to the state of a first dip switch 151, the CPU 62 in a fixture controls its lamp 41 either in dependence on intensity, duration and time base data on the serial link 16 addressed to that fixture, or by internally generating intensity, duration and time base signals. In the serial link control mode, the fixture address is determined by a second dip switch 153. In the internally controlled mode, a number read by CPU 62 from dip switch 153 represents the intensity, duration and time base that the CPU 62 will generate. <IMAGE>