GB282854A - Means for indicating current impulses - Google Patents

Abstract

282,854. Mix & Genest Akt.-Ges., and Lohaus, O. Sept. 22, 1926. Thermionic valve circuits. - Comprises an arrangement for causing a transient electric impulse to affect a relay for a substantial period of time. The apparatus may be connected to the line 4, in which the transient impulses are to be detected, by two condensers 3, 9 arranged as shown in Fig. 1. The condenser 3 is connected to the grid 1 which has a condenser 13 and leak resistance 12 and is earthed through a variable condenser 5 and resistance 7, while the condenser 9 is earthed through a condenser c and is connected to the filament 8. An additional grid g is coupled to the tuned circuit of a relay 11. The impedances are so adjusted that the normal A.C. in the line 4 does not effect a signal, but transient impulses cause a blocking charge to accumulate on the grid 1, and the resulting fall in output current operates the relay 11. In a simplification, Fig. 2 (not shown), the condensers c, 9, conductors 18 and grid g are discarded, the filament 8 is earthed, and the grid leak and condenser are connected between the grid 1 and conductor l. In a push-pull arrangement, Fig. 3, the line 4 is earthed through a coil 16 and a transformer t whereof the primary consists of the lead l and the secondary of a ring coil 17 whose middle point is earthed. In a modification, Fig. 4 (not shown), of the arrangement shown in Fig. 3 a single valve is used. Reference has been directed by the Comptroller to Specification 245,176.