GB737067A - Phase rotator - Google Patents

Abstract

737,067. Phase-shifting. BENDIX AVIATION CORPORATION. Oct. 23, 1953 [Oct. 30, 1952], No. 29383/53. Class 38 (2). A phase-shifting arrangement comprises a resistor 6 with ends connected together to an output terminal, voltages of equal magnitude and frequency but of opposite phase being supplied respectively to the resistor ends through resistor 4 and capacitor 5 and to a moving contact 11 on resistor 6, the phases of the two voltages being reversed as the contact passes the midpoint of the resistor. The antiphase voltages are developed at the anode and cathode of triode 1, having anode and cathode resistors 3, 2 of equal value, the grid being energized from a tapping on resistor 9 connected between one end of the secondary winding of transformer 7 and the centre point of that winding which is connected to the earthed, second output terminal. As the contact on resistor 6 is moved from one end to its centre, the output voltage changes in phase through a little less than 180 degrees. As the contact passes the centre, it is arranged that switch 8 connects resistor 9 to the other transformer output terminal, so that as the contact completes its travel to the other end of resistor 6, the output voltage continues to change until it has turned through somewhat less than 360‹ C. The moving contact 11 may be on a shaft 10 carrying a stepped cam 12 which operates a microswitch 8 at the midpoint of contact travel. In a modification, the output terminal and the condenser 5 are connected to the midpoint of resistor 6, Fig. 3 (not shown). The moving contact 11 may directly operate a toggle switch 8.