GB1434463A - Flash lamp circuit - Google Patents

Abstract

1434463 Flash-lamp control circuits INTERNATIONAL BUSINESS MACHINES CORP 14 May 1974 [26 June 1973] 21184/74 Heading H2H A flash-lamp circuit has an energy storage supply device comprising a charging means having a plurality of impedance levels, the arrangement being such that substantial recharging of the storage device after initiation of a flash is inhibited until the flash-lamp becomes de-ionized. Assuming a capacitor 13 to be fully charged from a D.C. source 14 by way of a resistor 19 in parallel with a thyristor 17, the thyristor will be non- conductive. Flashing of a lamp 10 is initiated by a signal applied to a terminal 26. This signal renders conductive a thyristor 24 whereupon a capacitor 23, previously charged from a D.C. source 32, discharges through the primary winding of a transformer 27, the resulting pulse from the secondary winding ionizes the lamp 10, the capacitor 13 then discharging therethrough to produce a flash. The signal at terminal 26 to initiate the flashing of lamp 10 is also applied to a delay circuit 33 which after a delay, sufficient to allow the lamp 10 to de-ionise, energizes a circuit 34 which produces a signal to render conductive the thyristor 17 whereupon the capacitor 13 is rapidly recharged. The resistor 19 is given a high ohmic value so as to severely limit the current supplied to the capacitor 13 and lamp 10 from the source 14 during flashing of the lamp 10 which current is insufficient to prolong the flashing of the lamp.