GB446031A - Apparatus for measuring the frequency of impulses - Google Patents

Abstract

446,031. Electric signalling systems. STRAUSS, S., 5, Pointengasse, and WEISGLASS, L., 56, Promenadenweg, both in Vienna. Jan. 17, 1935, Nos. 1643 and 1644. Convention dates, Jan. 18, 1934 and June 30, 1934. [Class 40 (i)] [See also Group XIX] Apparatus for measuring the fre quency of im. pulses such as pulse beats comprises a relay R which at each im. pulse connects a condenser C2 across a condenser C1, the condenser C2 being shortcircuited after each impulse. Condenser C1 is connected to a source V7 of constant potential and thus attains an equilibrium potential dependent upon the frequency of the impulses, this potential being measured by an electrostatic or thermionic valve voltmeter which is calibrated to indicate the frequency. The pulse beats are caused to act on a piezoelectric crystal K shunted by a resistance W and connected through an amplifier to the relay R, the armature of which is thus attracted at each pulse beat. The needle of an instrument J1 also oscillates at each beat. The condenser C1 is charged from the source V7 of constant potential through a resistance W10. At each beat, the relay R closes contacts 1, 2 to connect C1 across the smaller condenser C2. The contacts 1, 2 then open and contacts 2, 3 close to discharge thecondenser C2. The potential maintained on C1 is thus a measure of the frequency of the pulse beats. Contacts 4, 5 are closed by the relay R to connect a third condenser C3 in parallel with the condenser C1. The potential of C3, and thus of C1, is indicated by an ammeter J 3 in the plate circuit of a valve V3. This ammeter therefore gives a direct reading of the pulse frequency. The Specification as open to inspection under Sect. 91 describes also a glow tube which lights at each impulse and an ammeter arranged to indicate the amplitude of the impulses. This subject-matter does not appear in the Specification as accepted.