GB404734A - Improvements relating to rotary transformers for direct electric currents - Google Patents

Abstract

404,734. Rotary transformers. PESTARINI, G. M., 4, Tapton House Road, Sheffield. July 25, 1932, No. 20990. [Class 35.] The invention relates to a machine transforming continuous current at a fixed voltage and variable current into a substantially constant current at variable voltage or into a current which is related to the voltage in accordance with a desired law. The rotor consists of a normal continuous current armature 1 with primary and secondary brushes 5, 6 and 10, 11 respectively and the stator has a regulator winding 2 to maintain the speed constant. According to the invention, the regulator winding is supplied with continuouscurrent from two shunt excited machines 12, 13 connected in opposition and driven by the transformer, the machine 12 having a normally saturated field and the other 13 an unsaturated field ; the voltages of the two machines are equal at the desired transformer speed but when the speed departs from the normal, current flows in the appropriate direction through the winding 2, to correct the deviation. The secondary circuit instead of being connected across the secondary brushes 10, 11 may be in two parts, one part being connected across a primary brush and a secondary brush and the other part across the remaining brushes. The machine 12 may supply other circuits.