GB751401A - Improvements in or relating to ferroresonant flip-flop circuits - Google Patents

Abstract

751,401. Non - contact - making relays. INTERNATIONAL BUSINESS MACHINES CORPORATION. April 5, 1954 [April 8, 1953], No. 9887/54. Class 40 (4). In a ferroresonant circuit comprising resistance R, capacitance C and saturable inductance L connected in series across an A.C. source Eac, a trigger winding T is magnetically coupled to the inductance so as to produce a flux at right angles to the normal flux, whereby the circuit has bi-stable operating conditions without magnetic coupling between the trigger and inductance windings except during those periods in which both windings are energized. The inductor core material may be formed of thin magnetic ribbon 10 which in the arrangement shown in Fig. 8 is double-folded along the axis of grain orientation and is utilized as a trigger winding by welding or soldering a conductor 11 to its ends. Alternatively conductor 11, Fig. 9, constitutes the trigger winding and is positioned at the centre of a cylindrical roll of the core material. A single layer A.C. winding 12 is either directly wound on the core or is carried on an interposed section of sleeve insulation 13, Fig. 10. Two ferroresonant circuits may be arranged in parallel as shown in Fig. 3 and connected to the A.C. source through a common impedance Z which may be constituted by a resistor or inductive or capacitive reactance, the arrangement being such that pulses in the trigger windings T1, T2 cause the two circuits to change in opposite respects from one stable condition to the other. In a modified arrangement, Fig. 11, the trigger windings T1, T2 are connected to a single pulse input circuit and separate rectified and smoothed outputs are obtained across condensers C1, C2. As the common impedance Z is constituted by a capacitor 23, the D.C. output circuit is completed by an earthed resistor 24. Suggested applications are to counting circuits and shifting registers.