GB467872A - Improvements in and relating to electric regulating systems - Google Patents

Abstract

467,872. Automatic control systems. BRITISH THOMSON-HOUSTON CO., Ltd. May 22, 1936, No. 14570. Convention date, May 22, 1935. [Class 38 (iv)] E.m.f.-The voltage of a circuit is maintained constant by means of a transformer which is controlled in response to the current flow through an element having a non-linear voltamp. characteristic. In the form shown in Fig. 1 the secondary 5 of a booster transformer 3 is in series with a carbon-pile resistance 5 controlled by a thermal element 7 having a bimetallic strip 8 heated by eddy currents induced in a copper sleeve 10 by a winding 11 which is connected across the circuit through a non-linear resonant circuit 12, 13, 14. Variations in circuit voltage will produce exaggerated current variations through the winding 11. Momentary variations of circuit voltage will not affect the arrangement due to the heat enertia of the thermal element. In a modification Fig. 3, the transformer 3 is provided with a magnetic shunt 18 which is adjusted in response to voltage variations by a gas-filled bellows 15 having a heating winding 11 in series with the non- linear resonant circuit. In a further modification the transformer 3 is provided with series connected boosting and bucking secondaries the magnetic shunt varying the flux distribution between these windings. In another modification the transformer 3 has two primaries acting in opposition on a common secondary, one of the primaries being connected through the non-linear resonant circuit. Specification 450,298, [Group XXXVII], is referred to.