GB1426492A - Electric remote control apparatus - Google Patents

Abstract

1426492 Controlling by sound MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 28 Aug 1973 [30 Aug 1972 6 Dec 1972] 40488/73 Heading G4F [Also in Divisions H3-H5] Remote control of for example a television channel selector is effected by concurrent radio and ultrasonic signals. One acts as a subsidary signal, and either enables a gate to pass the main signal in the receiver (Figs. 1-4, not shown) or is mixed with the main signal (Figs. 5, 6, 7, not shown). The main signal, which can be either the radio or the ultrasonic one, may have two components at different frequencies (f 1 , f 2 with radio as main signal, Figs. 3, 6 not shown; F1 F2 with ultrasonic as main signal, Figs. 4, 7, not shown). The two frequencies are separated by discriminators to operate respectively on-off-volume controls, and channel selector control. At the transmitter (Fig. 8, not shown), a striker (24) simultaneously strikes a metal element (23) acting as ultrasonic transducer; and a piezo-electric transducer (20), the latter causing a spark in an air gap (11) to produce R.F. emission from antenna (25) at the frequency of a tank circuit (22). The elements (23, 20) may be cemented together. Transistor receivers and discriminators are described in an exemplary receiving circuit (Fig. 9, not shown).