Multiple disposable photographic flash bar - uses electronic circuit to trigger flash bulbs grouped in pairs with each second bulb containing fusible switch to control firing sequence

摘要

The array uses ten flash bulbs electrically coupled in pairs, with a fusible switch in one of each pair of lamps to enable the operation of the second lamp in the pair. Five thyristor circuits are used to provide the switching of current to each pair of flash lamps. The lamps are laid on flat board with seven contact pads along the edge which is plugged into the electronic circuit housed in the camera. Each second lamp contains a fusible switch which is insulating until exposed to heat. The closing of this switch connects the next lamp in the array to the trigger thyristor. The thyristor is gated by a transistor circuit which inhibits thyristor operation if the preceding fusible link is open circuit.