US3729710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency selective remote control system
Assignee: Western Microwave Laboratories Inc
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Filing: 1971-12-28
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Granted: 1973-04-24
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Expires: 1991-12-28
Abstract
Abstract A system for selectively controlling the operation of a plurality of devices, e.g., the electrically operable water valves for an irrigation system, which are coupled across a twowire power line. Each of the devices is provided with a frequency responsive circuit or decoder which responds to a signal of only a single frequency to connect the device across the line. The control of the decoders is provided by the output signal of an Nchannel encoder which, although it can generate only a single frequency at a time, provides a sequence of the selected frequencies needed to operate selected devices in time multiplex. By providing each of the decoders with a capacitive circuit which has a fast charge-slow discharge characteristic in response to a signal of the associated predetermined frequency, and by rapid time sequencing of the signals produced by the fixed encoder, it is possible to simultaneously operate any number of the devices in a random fashion. To provide local selective control of any one of the devices, the system also includes a portable encoder which can selectively produce a signal of any one of the predetermined frequencies necessary to operate a device. When energized, the portable encoder also provides a high frequency output signal which disables the fixed encoder. Preferably, in order that the system be simple and as inexpensive as possible, output signals from the encoders are transmitted to the decoders and the pilot frequency output of the portable encoder is transmitted to the fixed encoder by superimposing the output signal from the encoders on the power line signal. To achieve this, plug-in connections are provided for the portable encoder at spaced locations along the power line.
Inventors
- 👤 R Sherwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:29
CPC Classifications
H; H04; H04Q; H04Q9/00; H04Q9/08; H04Q9/10; H02; H02J; H02J1/00; H02J1/06; H02J13/00; H02J13/13; H02J13/1317; H02J13/1319
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
273 words
A frequency selective control system comprising in combination a source of electrical power; a two-wire power line connected to said power source; a plurality of electrically operable devices spaced along said power line; a like plurality of frequency selective circuit means, one for each of said electrically operable devices, each of said frequency selective circuit means being responsive to an input signal of a different predetermined frequency for selectively connecting its associated electrically operable device across said two-wire power line to energize same; a programmed stationary encoder circuit means for selectively providing output signals of said different predetermined frequencies, said encoder circuit means including time division multiplexing means for causing said encoder circuit means to continuously provide the output signals of selected different frequencies in a predetermined sequence and for a predetermined time within said sequence; means for coupling the output signals from said encoder circuit means to the input of each of said frequency selective circuit means; a portable encoder circuit means for selectively providing an output signal of a selected one of said predetermined different frequencies and for simultaneously providing a pilot tone output signal having a predetermined frequency which is substantially higher than the range of frequencies provided by said stationary encoder circuit means; control circuit means responsive to said pilot tone signal for causing said stationary encoder circuit means to cease providing output signals whenever said pilot tone signal is being received; and means for coupling the output signals from said portable encoder circuit means to the inputs of said plurality of frequency selective circuit means and said control circuit means whenever said portable encoder circuit means is energized.
Claim 2
Dependent Claim
273 words
A frequency selective control system comprising in combination a source of electrical power; a two-wire power line connected to said power source; a plurality of electrically operable devices spaced along said power line; a like plurality of frequency selective circuit means, one for each of said electrically operable devices, each of said frequency selective circuit means being responsive to an input signal of a different predetermined frequency for selectively connecting its associated electrically operable device across said two-wire power line to energize same; a programmed stationary encoder circuit means for selectively providing output signals of said different predetermined frequencies, said encoder circuit means including time division multiplexing means for causing said encoder circuit means to continuously provide the output signals of selected different frequencies in a predetermined sequence and for a predetermined time within said sequence; means for coupling the output signals from said encoder circuit means to the input of each of said frequency selective circuit means; a portable encoder circuit means for selectively providing an output signal of a selected one of said predetermined different frequencies and for simultaneously providing a pilot tone output signal having a predetermined frequency which is substantially higher than the range of frequencies provided by said stationary encoder circuit means; control circuit means responsive to said pilot tone signal for causing said stationary encoder circuit means to cease providing output signals whenever said pilot tone signal is being received; and means for coupling the output signals from said portable encoder circuit means to the inputs of said plurality of frequency selective circuit means and said control circuit means whenever said portable encoder circuit means is energized.
Claim 3
Dependent Claim
48 words
The apparatus defined in claim 1 wherein said electrically operable devices are normally closed fluid valves, each of which leads to at least one separate outlet and each of which is connected to a fluid supply conduit, whereby said system comprises a remotely controlled selective fluid distribution system.
Claim 4
Dependent Claim
52 words
The apparatus defined in claim 1 further including a plurality of plug type connectors connected across said power line at spaced intervals, and a mating plug type connector for connecting the output of said portable encoder circuit means across said power line, and for supplying power to said portable encoder circuit means.
Claim 5
Dependent Claim
115 words
The apparatus defined in claim 3 wherein the input of said control circuit means and the inputs of each of said frequency selective circuit means are connected across said power line; and wherein said coupling means for the output signals of said stationary encoder circuit means includes a first means for modulating the electrical power signal in said power line with the output signals from said stationary encoder circuit means; and wherein said coupling means for the output signals from said portable encoder circuit means includes a second means, contained in said portable encoder circuit means, for modulating the power signal in said power line with the output signals from said portable encoder circuit means.
Claim 6
Dependent Claim
17 words
The apparatus defined in claim 4 wherein said first and second means fOr modulating are shunt modulators.
Claim 7
Dependent Claim
234 words
The apparatus defined in claim 1 wherein said stationary encoding circuit means comprises: a source of clock pulses; a multistage binary counter for counting the clock pulses; a plurality of decode AND gates, one for each of the predetermined different frequencies, each of said gates having a plurality of inputs connected to a different combination of the outputs of the stages of said binary counter corresponding to different predetermined counts of said binary counter; a further plurality of AND gates each of which has its output connected to a further input of a separate one of said decode AND gates, each of said further plurality of AND gates having a pair of inputs with one of said pair of inputs of each of said gates being connected to the output of said multiplexing means; programming means for applying a signal to the other input of selected ones of said further plurality of AND gates according to a predetermined program to determine the frequencies which are to be generated and the times therefor; a summing gate means responsive to an output signal from any of said decode AND gates for providing an output pulse which resets said binary counter to begin counting again; and a flip-flop connected to the output of said summing gate means and toggled by the output pulses therefrom whereby the output of said flip-flop constitutes the signal of the desired frequency.
Claim 8
Dependent Claim
63 words
The apparatus defined in claim 6 wherein said stationary encoder means includes a further decode AND gate having its inputs connected to a combination of outputs of the stages of said binary counter which correspond to a count greater than that to which any of the other decode AND gates responds, and its output connected to an input of said summing gate means.
Claim 9
Dependent Claim
29 words
The apparatus defined in claim 6 wherein said control circuit means includes means for disabling the output signals from said programming means whenever said pilot tone signal is received.
Claim 10
Dependent Claim
103 words
The apparatus defined in claim 1 wherein each of said frequency selective circuit means comprises: a tank circuit tuned to a particular frequency; a capacitive circuit means having a fast charge-slow discharge characteristic connected to the output of said tank circuit, said capacitive circuit means having a discharge time which is long relative to the sampling rate of said multiplexing means; and means responsive to the voltage across the capacitor of said capacitive circuit means for completing the power circuit between said powerline and the associated electrically operable device, whereby a plurality of said electrically operable devices may be continuously and simultaneously energized.
Claim 11
Dependent Claim
72 words
The apparatus defined in claim 9 wherein said capacitive circuit means includes a transistor connected as an emitter follower and a storage capacitor connected in the emitter circuit path thereof; and wherein said means for completing the power circuit includes a Schmitt trigger having its input connected across said storage capacitor and its output connected to a power switch, said power switch, when closed, connecting said electrically operable device across said powerline.
Claim 12
Dependent Claim
75 words
The fluid distribution system defined in claim 2 wherein said portable encoder circuit means includes: a source of frequency clock pulses; a frequency divider means connected to the output of said source of clock pulses for providing said pilot tone signal at the output thereof; a frequency generator for selectively providing an output signal having one of said plurality of different predetermined frequencies; and selector means for controlling the output frequency of said frequency generator.
Claim 13
Dependent Claim
18 words
The fluid distribution system defined in claim 11 wherein said frequency divider means is a multistage binary counter.
Claim 14
Dependent Claim
164 words
The fluid distribution system defined in claim 12 further including a plurality of plug type connectors connected across said power line at spaced intervals, and a mating plug type connector for connecting said portable encoder circuit means across said power line, and for supplying power to said portable encoder circuit means, and wherein: the input of said control circuit means and the inputs of each of said frequency selective circuit means are connected across said power line; said coupling means for the output signals of said stationary encoder circuit means includes a first means for modulating the electrical power signal in said power line with the output signals from said stationary encoder circuit means; and said coupling means for the output signals from said portable encoder circuit means includes a second and third means, contained in said portable encoder circuit means, for modulating the power signal in said power line with the output signal from said frequency divider means, and said frequency generator respectively.
Claim 15
Dependent Claim
19 words
The fluid distribution system defined in claim 13 wherein said first, second and third modulating means are shunt modulators.
Claim 16
Dependent Claim
237 words
The fluid distribution system defined in claim 14 wherein said stationary encoding circuit means comprises: a source of clock pulses; a multistage binary counter for counting the clock pulses; a plurality of decode AND gates, one for each of the predetermined different frequencies, each of said gates having a plurality of inputs connected to a different combination of the outputs of the stages of said binary counter corresponding to different predetermined counts recited by said binary counter; a further plurality of AND gates each of which has its output connected to a further input of a separate one of said decode AND gates, each of said further plurality of AND gates has a pair of inputs with one of said pair of inputs of each of said gates being connected to the output of said multiplexing means; programming means for applying a signal to the other input of selected ones of said further plurality of AND gates according to a predetermined program to determine the frequencies which are to be generated and the times therefor; a summing gate means responsive to an output signal from any of said decode AND gates for providing an output pulse which resets said binary counter to begin counting again; and a flip-flop connected to the output of said summing gate means and toggled by the output pulses therefrom whereby the output of said flip-flop constitutes the signal of the desired frequency.
Claim 17
Dependent Claim
44 words
The fluid distribution system defined in claim 14 wherein the outputs of said first and third shunt modulators are connected to said power line via a high frequency choke which presents a high impedance to signals of the frequency of said pilot tone signal.
Claim 18
Dependent Claim
115 words
The fluid distribution system defined in claim 2 further including a plurality of said stationary encoder circuit means spaced in the field throughout said distribution system, each of which selectively provides the frequency signals for a portion of the total number of said fluid valves, each of said stationary encoder circuit means including a further control circuit means responsive to a control signal of a different frequency for alternately enabling or disabling the associated stationary encoder circuit to provide output signals each time a control signal of the associated frequency is received; and a central master controller having its output connected to each of said further control circuit means for selectively providing said control signals.
Claim 19
Dependent Claim
37 words
The fluid distribution system defined in claim 17 wherein said portable encoder circuit means includes means for selectively providing an output signal having the frequency of one of said control signals for said stationary encoder circuit means.
References Cited (Backward Citations)
US3691528A
Cited
US3689886A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |