GB979644A - Improvements in and relating to electric signal apparatus - Google Patents

Abstract

979,644. Reverberation systems; electromechanical delay lines. PHILCO CORPORATION. June 27, 1961 [June 27, 1960], No. 23201/61. Headings H3U, H4J and H4R. In a sterophonic reproducing system a reverberation effect is produced by feeding a common signal derived from the two channels of the apparatus through a delay device and mixing the delayed signal with each of the two normal channel signals feeding the reproducing means. A mis - matched torsional delay line device is described which produces multiple echoes. Circuit details, Fig. 1. The two channel inputs A and B are fed respectively to valves 14A and 14B from each of which two signals are developed, i.e. at anode and cathode. The anode signals are mixed in a resistive adding network and fed to valve 46 the anode of which feeds the delay device 48, the delayed output is fed via an RC filter to amplifier valve 86 and attenuators 102 and 104, the delayed signal from the slider of attenuator 104 is then mixed with the normal channel signals by feeding it to the grids of valves 22A and 22B, the cathodes of which are fed with the respective channel signals from the cathodes of valves 14A and 14B. The anodes of the valves 22A and 22B are fed to the respective reproducing systems. Delay device, Fig. 2. Signals fed to coil 80 causes rotation of the diametrically magnetized rotors 68 and 74 which are mounted at the ends of springs 60 and 62. The rotational displacement travels down the springs and causes rotation of the magnetized rotors 72 and 76 and hence generation of corresponding signals in coil 84. The springs are attached at each end to rigid supports 64 and 66 which represent mismatched terminations and cause multiple reflections.