REMOTE CONTROL SYSTEM

摘要

Transmitters (1) of remote control systems are provided with surface­acoustic-wave-resonators (42) and receivers (2) are provided with variable inductors (54,79) for aligning the receiver, to optimise the performance versus the costs. A receiver oscillating-filtering circuit (24) comprises a single transistor (74), capacitors (76,77) and a variable inductor (79) to create a kind of "filtering" oscillator. A receiver ripple rejecting circuit (25) improves the operation of the receiver oscillating-filtering circuit 24 and of a receiver amplifying circuit (23) comprising a cascade design of two transistors (66,67). A receiver filtering circuit (26) between the receiver oscillating­filtering circuit (24) and a receiver amplifying-shaping circuit (27) improves the operation of the latter. A transmitter oscillating-amplifying circuit (12) comprises a single power transistor (46) operating as a Colpitts oscillator. The remote control system avoids ceramic-resonators and chokes, and the receiver (2) avoids surface­acoustic-wave-resonators. Power consumption is minimised.