摘要 |
A flashbulb in which a filament and paste are not required. The flashbulb is not only cheaper but is faster in operation. This is primarily achieved by ensuring that the mass of finely-shredded combustible metal strips provided in such flashbulbs are in contact with the lead-in current conductors in the bulb. Due to the oxidizing atmosphere, the strips have an electrically-insulating skin. It has been found that this skin can readily be broken down by the momentary application of a voltage, whereupon the strips form a current-conducting path between the electrodes and ignition can then be affected with a voltage lower than the breakdown voltage. |