GB675659A - Improvements relating to voltage regulators and reversers employing rectifiers - Google Patents

Abstract

675,659. Code telegraphy. ROQUET, R. J. C. Aug. 10, 1948 [Aug. 27, 1947], No. 21123/48. Class 40 (iii). [Also in Group XXXV] A voltage-regulating and reversing device for supplying an output circuit with a direct current voltage whose polarity can be reversed at will, the said voltage being maintained constant in absolute value independently of polarity reversals, is constituted by a network comprising a change-over switch, rectifying cells, a direct-current voltage standard and one or more auxiliary voltage sources and resistances, the arrangement being such that the voltage drop across a resistance connected between the associated voltage source and the output circuit adjusts itself so that the voltage applied to the output circuit is equal to the voltage of the voltage standard, and the arrangement of the network and the values of the resistances being chosen in such a way that the deviations of the actual voltage of the said auxiliary sources has a minimum or almost negligible effect upon the voltage across the terminals of the output circuit. In the arrangement shown, the modulating key M, which may be controlled by a telegraph transmitter, is associated with batteries E2, E<SP>1</SP>2 in an arm BD of a network comprising an arm EF of resistance r3 and two arms BE, FD, together with diagonals DE, BF including rectifiers C1, C2, C3, C4. When the switch is moved to the position (1) the voltages at the corners of the network are such that current passes in the arms BE, FD and the diagonal arms are blocked, as indicated by Fig. 2 (not shown), so that apart from a small current which may flow through the battery E1, the standard voltage is applied to the output circuit VT at the terminals Al, A2. When the arm M moves over to the position (2) the reversed voltages applied by battery E<SP>1</SP>2 at the points B, D alter the relative magnitudes of the voltages at the points B, D, E, F so that the rectifiers C2, C3 in the diagonals of the lattice.network become conducting, and effectively the potential of the standard source E1 is applied with reverse polarity to the output line VT as indicated by Fig. 3 (not shown). In a modification, Fig. 4 (not shown), the positive and negative potentials corresponding to E2, E<SP>1</SP>2 are derived from a single battery forming a diagonal of a Wheatstone bridge arrangement. It is shown mathematically in the Specification that if i1 is not exactly zero the variations of output voltage will be dependent on E2, E<SP>1</SP>2 and that the change of current or effective voltage is small and is a small fraction of the variation which would be produced by the variation of the voltage of the batteries E2, E<SP>1</SP>2 constituting the auxiliary voltage sources. The auxiliary voltage source or sources, the associated resistances and the change-over switch may be located at a distance from the remainder of the network and a single voltage standard may be employed to supply simultaneously a plurality of voltage-regulating and reversing networks.