STROBE_LIGHT

Published:2009/6/24 23:34:00 Author:May | From:SeekIC

This strobe light operates from standard 120-Vac power，R1 limits the amount of current applied to the voltage doubler stage，which is comprtsed of C1，C2，C3，D1，D2，C4，C5，and C6 Capacitors C1，C2，and C3 are connected in parallel and form a capacitance of 30 μF at 160V. Capacitors C4， C5， and C6 are connected in serles and form an equivalent capacitor of about 53 μF at 480 V . Diodes D1 and D2 not only rectify the ac voltage，but also complete the vltage doubler stage，which convertsthe incoming 120 Vac to the appropriately 300 V that are required by the xenon strobe tube. The next stage of the circuit is the neon relaxation oscillator and trigger stage This stage is made up of R2， P1，C7，L1，Q1，T1，and T2．As the storage capacitor (made up of C4，C5，and C6) reaches its full-capaclty charge，the voltage divider (made up of R2 and P1) applies voltage to capacitor C7. As C7 charges up，it reaches a threshold voltage level，SCR Q1. When Q1 has a positive pulse on its gate，it fires(causes a short from anode to cathode). That firing action discharges most of the energy stored in C7 into trigger transformers T1 and T2(which have secondaries connected in series to developer 8 kV). The frequency of the 8-kV pulses is determined by the setting of P1 and the value of C7. Because C7 is a fixed capacitor，only the Setting of P1 adjusts the flash rate in this circuit As soon as an 8-kV pulse is applied from the secondary of T2 (trigger wire) to the trigger lead of FT1，it discharges storage capacitors C4，C5，and C6，which causes it to ionize (flash). The cycle thenrepeats itself until the power is removed from the circuit board by turning off S1 or removing the line cord.



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