PLURAL CHANNEL FM REMOTE CONTROL SYSTEM

• US 3,835,454 A
• Filed: 10/10/1972
• Issued: 09/10/1974
• Est. Priority Date: 10/10/1972
• Status: Expired due to Term

• Current Assignee: Douglas M. French, Joseph Palmieri
• Original Assignee: Douglas M. French, Joseph Palmieri
• Inventors: Palmieri, Joseph, French, Douglas M.
• Primary Examiner(s): Yusko, Donald J.
• Application Number:
  US05/296,268
• Time in Patent Office: 700 Days
• Field of Search: 340/171R,147PC,167R,167A,183,349 325/30,64 343/225
• US Class Current: 340/12.16
• CPC Class Codes: G08C 15/12 the signals being represented by pulse characteristics in transmission link

Abstract

A system for individually adjusting a plurality of remotely located servo units according to the adjustment of a manual control for each unit by transmitting an FM carrier signal that is broken into a plurality of segments with each segment including a portion having a low frequency and another portion of a high frequency with the duration of each segment being related to the setting of its manual control. An FM receiver decodes the wave to produce an electrical pulse related to the duration of each segment with the associated servo unit assuming a position that is related to the pulse duration. The transmitter is capable of selecting any one of a plurality of different carrier frequencies and if each device receives only one of the carrier frequencies, the transmitting may select the device to be controlled.

Claims

1. A remote control radio system comprising a plurality of adjustable controls with each control supplying a signal related to its adjustment, a radio transmitter for transmitting a radio wave at a carrier frequency, means for subdividing the radio wave into a continuously repeatable sequence with each sequence having a plurality of segments, there being one segment associated with each control, means for causing each segment of the wave to have a portion of the segment on one frequency and the remaining portion of the segment on another frequency with both frequencies being near the carrier frequency and means for relating the duration of each segment to the signal supplied by its associated control;

and a device located remotely from the transmitter and having a plurality of servo units with there being one servo unit for each control, each of said servo units having means for producing a response that is related to the duration of an electrical pulse supplied thereto, a receiver in the device having an antenna for receiving the transmitted wave and demodulating each segment of the wave into an electrical pulse having a duration related to the duration of the segment and means for directing the pulse from the same segment in each sequence to the same servo unit to cause said servo units to respond to the duration of the pulse directed thereto.

2. The invention as defined in claim 1 in which the means for causing the two portions of different frequencies includes a frequency modulating means responsive to the value of a voltage applied thereto to vary the frequency and in which there are means for providing a voltagE shiftable between two values to said frequency modulating means.

3. The invention as defined in claim 2 in which the shiftable voltage supplying means includes a clock for producing a cycle for each segment consisting of a part having a voltage of one value and a remaining part having another value and means for varying the duration of each cycle including connections to the manual controls.

4. The invention as defined in claim 1 in which the means for relating includes means for permitting the signal from only one control to be effective to control the duration of a segment and means for sequentially permitting the signals from the controls to be effective.

5. The invention as defined in claim 4 in which the permitting means includes a counter having a plurality of count terminals at which an indication of the count of the counter appears, a plurality of switch means with there being one switch means connected to each control and means connecting one count terminal to one switch to cause the switch means to be operative to permit its control to vary the duration of a segment only when the counter has the indicated count associated with each switch means.

6. The invention as defined in claim 5 in which there are means for shifting the counter one count with the appearance of each segment.

7. The invention as defined in claim 1 in which there are means for maintaining substantially constant the duration of the one portion of each segment, in which the duration of the other portion is regulated by the means for relating and in which the duration of the demodulated electrical pulse equals the duration of the segment producing same.

8. The invention as defined in claim 1 in which the means for causing includes a variable frequency clock having an output at one or another voltage level and means for adjusting the duration of one of the voltage levels.