GB293387A - Arrangements for increasing the sensitiveness of alternating current instruments - Google Patents

Abstract

293,387. Siemens - Schuckertwerke Akt.-Ges., (Assignees of Siemens-Schuckertwerke Ges.). July 5, 1927, [Convention date]. Current and pressure meters.- The sensitiveness of an alternating-current measuring-instrument or relay, Fig. 2, is increased by connecting in series therewith an iron-cored inductance coil 3, the instrument 2, in series with the inducance 3, being connected across a low - resistance shunt 5 in the main circuit 4. Resistances, inductances, or capacities, or combinations thereof, may be associated with the instrument. The measuring or relay circuit, or the hole circuit, may be tuned to the frequency of the supply voltage by adding a condenser. Harmonics developed in the iron core of the inductance are thereby suppressed. Transformers may be interposed between the instrument and the inductance. The Specification as open to inspection under Sect. 91- (3) (a) states also that a voltmeter 2, Fig. 2 (Cancelled) may be similarly connected in series with an iron-cored inductance 3, and also that two capacities or oscillation circuits may be connected in parallel, so as to form a short-circuit for high-frequency oscillations. This subjectmatter does not appear in the Specification as accepted.