Accession Number : ADD004861

Title :   Sliding Tone Command Receiver System.

Descriptive Note : Patent,


Personal Author(s) : Williamson,P Roger

Report Date : 14 Mar 1978

Pagination or Media Count : 7

Abstract : The system employs a sliding tone FM signal to command a remote device such as a balloon; for example, to fire a squib for balloon release. The tone is a slowly-changing, progressively-increasing signal received and detected by discriminator circuitry for application to a phase-locked loop circuit. Comparison of the loop output with a reference voltage provides a release signal when the reference voltage is exceeded. Since the reference voltage is determined by the loop voltage produced by a predetermined command tone, the generation of the release signal is dependent upon the presence of that particular command frequency. A unijunction transistor and an SCR then function as a relay to close a battery-squib circuit. The slowly-changing, sliding tone, as well as the time constant of the phase locked loop circuit, provide a high degree of security from accidental commands and also permit a wide variation in component tolerance including temperature tolerance. Simplicity and low cost permit the receiver to be considered expendable. (Author)

Descriptors :   *Patents, *Radio receivers, *Command and control systems, Audio tones, Frequency modulation, Low costs, Silicon controlled rectifiers

Subject Categories : Electrical and Electronic Equipment
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE