Patent GB-411832-A (GB)
Title: Electric regulating and control systems
IPC: G05F1/34
Filed: 1932-12-02
Abstract: 411,832. Control systems for consuming devices; automatic regulation; transformers. FITZGERALD, A. S., 433, Warwick Road, Wynnewood, Pennsylvania, U.S.A. Dec. 2, 1932, No. 34209. [Classes 38 (ii) and 38 (iv).] To regulate transmission from an alternating current source or circuit to a load circuit anumber of conducting paths are provided, each containing a reactance with a saturable core and the core of the reactance in the path to be employed is saturated, the others remaining unsaturated. Fig. 1 shows a transformer 2 with end terminal 16 and taps 26, 36, 46 connected to a load circuit 9 through reactances 17, 27, 37, 47, the core of any one of which can be saturated so as, in effect, to connect the corresponding tap to the loadcircuit by the means to be described. The saturating windings of the reactances 17, 27, 37, 47 are connected through rectifiers 10, 20, 30 40 to a device 1 which selects the winding to be energized in accordance with the ratios of the currents supplied to the terminals 5, 6, 7, 8 as described in Specification 411,831, [Group XXXVIII]. The terminals 5, 6, 7, 8 are connected through rectifiers 28, 29 to a tapped impedance 23, 24, 25 and impedances 19, 22 which are connected in such a way that the ratio of the currents through the rectifiers 28, 29 can be given any desired value by adjusting the values of the impedances 19, 22. To effect this, the impedance 22 is formed as a reactance with a saturating winding, the current through which is regulated in accordance with the voltage in the load circuit 9. For this purpose an arrangement similar to that described in Specification 400,206 is employed comprising a bridge device 310 which is balanced at normal voltage, but when the voltage is disturbed, transmits current to a transformer 340 in a direction depending on whether the voltage is in excess or defect. The transformer 340 has two windings connected to the grids of the two valves 410, 420, the plate circuits of which are oppositely connected to a condenser 290 which is connected to the grid of a valve 280 so that the conductivity of the valve rises above or falls below the normal in accordance with the variations of voltage in the circuit 9. The saturating winding of the reactance 22 is supplied with current through the valve 280. Fig. 3 shows an arrangement for producing a backing or boosting effect. The transformer 2 has a shunt winding 13 and a secondary winding 14 with terminals 16, 46 and taps 26, 36 connected to the supply circuit 15 and the load circuit 9 through saturable reactances 17<A>, 47<A>, 27<A>, 37<A> and 17<B>, 47<B>, 27<B>, 37<B> respectively. For full boost the cores of the reactances 17<A>, 47B are saturated and as the cores of 27<A>, 37<A>, 47<A> are saturated the boost is diminished to neutral ; the core of 47n may then be kept saturated and the cores 37B, 27B, 17<B> saturated in succession to give increasing buck. For this purpose there are provided two devices 1<A>, 1B of the type described in Specification 411,831 and two bridge devices 18<A>, 18B and a valve 280 as described in connection with the former modification. The valve 280 is connected to the grids of two valves 38<A>, 38B in parallel and shunted by a resistance 42 in such a way that the valve 38A is first rendered conductive and its conductivity increases while the cores of 17<A>, 27<A>, 37<A> 47<A> are successively saturated when the valve becomes saturated ; the conductivity of the valve 38B then begins to increase regulating the saturation of the cores of 17B, 27<B>, 37B, 47B. Specifications 400,266 and 404,034, [Group XXXIX], also are referred to.