GB964252A - Improvements in and relating to electric signal systems - Google Patents

Abstract

964,252. Binaural systems. PHILCO CORPORATION. Feb. 1, 1961 [Feb. 1, 1960; March 14, 1960], No. 3784/61. Headings H4J and H4R. An electric signalling system comprises two push-pull stages 32, 41 (Fig. 1), for respective stereophonic input signals 30, 31, each stage 32, 41 including a respective output transformer 36, 45 having two primary windings 37 and 38, 46 and 47, and there being a third output transformer 50 common to both stages 32, 41 and having a primary 51 defined by primary winding sections. The two primary windings of each of the transformers 36, 45 are connected in pushpull relationship by connections through primary sections of transformer 50. Transformer 50 is connected in push-pull relationship in both stages 32, 41 and presents a low impedance to signals of higher audio frequencies. Lower audio frequency components of both input signals 30, 31 appear at the secondary winding of transformer 50 for monophonic reproduction by a sound reproducer 53 connected thereto, and the higher audio frequency components of both signals 30, 31 are reproducible stereophonically by respective sound reproducers 40, 49. The low impedance of transformer 50 to higher frequencies is provided by capacitor 54. Transformer 50 may comprise two windings connected one to each stage 32, 41, each with an intermediate tapping defining two primary sections (Fig. 2, not shown). Transistor amplifiers may be used in place of valves 33, 34, 42, 43.