GB1295631A - - Google Patents

Abstract

1295631 Projectile fuzes BOLKOW GmbH 14 May 1968 [6 July 1967] 22944/68 Heading F3A An electrical detonator 4 is connected to contacts 1a, 1b situated on the exterior of a projectile casing and connectible temporarily to an external electrical supply 10. When the supply 10 is connected it charges a condenser 2 through a switching spark gap 3, e.g. a glow switch. The supply voltage 22 is chosen to be only slightly greater than the strike voltage of the gap 3 to ensure that the condenser voltage 20 remains below the strike voltage and thus prevent discharge of the condenser should the contacts 1a, 1b become accidentally shortcircuited. A switch 5 closed by a clockwork mechanism 6 causes the condenser 2 to discharge through the detonator 4 after a time delay. In a modification (Fig. 4, not shown) the voltage of the supply 10 is slightly less than the strike voltage of the spark gap 3 but has a number of periodically occurring voltage peaks of a value greater than the strike voltage. However, only a single voltage peak is necessary since the gap 3 continues to conduct once it has been struck. In a further modification. Figs. 5, 6, the circuit of the supply 10 includes a resistance 12 and capacitor 11, the spark gap 3 becoming conducting each time the difference of the voltages 26 and 20 across the capacitor 11 and 2 becomes equal to the strike voltage 21. Thus the capacitor 2 is charged in steps and the charging may be stopped after a desired number of steps by a counting operation. To ensure that the voltage 20 does not exceed the strike voltage 21 the magnitude of the supply voltage 22 or the number of charging steps are limited accordingly. The mechanism 6 of Fig. 1 is omitted and instead the switch 5 is closed by impact of the projectile so that the capacitor 2 charges a capacitor 8 through a resistor 7. When the voltage across capacitor 8 equals the strike voltage of a further spark gap 9, the detonator 4 operates.