US3621142A - Single wire dc communicating means - Google Patents

Abstract

Means for communicating over a single-wire DC circuit disposed between two voltage controllers or regulators wherein the output of a first controller or regulator is altered or modulated by an impressed signal voltage and a receiver is connected to the wire prior to the second voltage controller or regulator to receive the modulated or altered DC voltage and reproduce the signal voltage.

Description

United States Patent lnventor Earl L. Bunting [56] References Cited A l N UNITED STATES PATENTS m 5 1969 2,193,061 3/1940 Davis 179/14 Patented 13,1971 2,682,640 6/1954 179/1 A Assignee Bunting Ster1Systems,lnc. 10 8/1959 [79/ l Bridgeport, C 2,831,067 4/1958 179/81 B 3,027,429 3/1962 179/1 HF 3,531,594 9/1970 Dilkerson 179/1 H Primary Examiner-Kathleen H. Claify M Assistant Examiner-Jon Bradford Leaheey Attorney-Johnson & Kline SINGLE WIRE DC COMMUNICATING MEANS ABSTRACT: Means for communicating over a single-wire DC 4 claims 1 Drawing 8. circuit disposed between two voltage controllers or regulators wherein the output of a first controller or regulator is altered US. Cl 179/1 H or modulated by an impressed signal voltage and a receiver is In!- Cl 1 connected to the wire prior to the second voltage controller or Field Of Search... 179/14, 1 regulator to receive the modulated or altered DC voltage and 1 1 84 31 /1 reproduce the signal voltage.

/2 0 6/ g SO U R C E 50 SINGLE WIRE DC COMMUNICATING MEANS The present invention provides a simplified system wherein a single-wire DC circuit is connected to a DC source through a voltage regulator whose output is modulated or changed by a predetermined signal. This is accomplished by utilizing a transistor-type voltage regulator having a base connected to ground through a suitable controlled circuit to produce a predetennined output DC voltage, less than the source voltage, on a single coaxial wire or pair extending to a second similar voltage regulator having a lower output than the first regulator and by impressing a signal voltage on the voltage control such as the base of a transistor acting as the first regulator to alter the output. For example, if it is desired to have audio communication over this wire, an AC audio signal voltage is produced, as by a microphone or the like, and applied through an amplifier or otherwise to the base of the voltage regulating transistor to modulate the DC output of the voltage regulator in accordance with the frequency of the signal.

It two-way communication is desired, an audio or other return signal source, such as a microphone or the like, is connected through an amplifier to the interconnecting wire prior to the second voltage regulator to impress the audio or other signal thereon and a receiver or speaker is connected to the wire between the said connection and the first regulator to reproduce the signal.

Other features and advantages of the invention will be apparent from the specification and claims when considered in connection with the accompanying drawing wherein the FIGURE shows a circuit of the present invention.

As shown in the drawing, a single-wire DC circuit is series-connected at one end to a source of DC voltage 11 through a transistor-type voltage controller or regulator 12 which has its emitter terminal 13 connected to the source of voltage; its collector terminal 14 connected to the wire 15 of the DC circuit and its base 16 connected to ground through a zener circuit 17, comprising a zener diode l8 and a choke coil 19, which controls the output of the voltage regulator at a value less than the source voltage. A resistor 20 is connected to the source 11 and to the conductor 21 between the zener diode l8 and base 16 to maintain the transistor conductive at the voltage as produced by the zener circuit.

The other end of the wire 15 is connected to the emitter terminal 13a of a similar voltage controller or regulator 22 having its base 16a connected to ground by a zener circuit 23 having zener diode 24 to control the output from the collector 140 at a value less than the regulator 12. This output from collector 14a is connected to and operates a suitable load 25. A resistor 26 is connected between line 15 and the conductor 27 extending between the zener diode 24 and the base 16a to maintain the transistor of the voltage regulator 22 conductive at the voltage as produced by the zener diode.

In accordance with the invention, an AC signal source is provided which produces a signal of predetermined voltage and when the signal voltage is impressed on the base 16, the output of the voltage regulator 12 is altered or modulated in accordance with the signal voltage. wire 15, and prior to the voltage regulator 22, a receiver 28 is connected to receive the modulated output of the regulator 12 and respond to the signals.

While the signal source can be a video camera or a control signal generator and the receiver can be a monitor or a control signal reproducer, in the herein illustrated form of the invention the signal source produces an audio signal and comprises a microphone 29 connected through an amplifier 30, to produce an AC signal voltage. The amplifier is powered from the DC line 15 through filter 30a. The amplifier is connected by switch means through potentiometer or outgoing volume control 32 to the zener circuit 17, as shown, and applies thereto the required AC signal voltage to modulate the output of the voltage regulator 12.

At the other end of the While the switch could be a voice-controlled relay, it is herein illustrated as a normally open push-to-talk switch 31. The receiver 28 is a speaker 35 connected to the line through a condenser 36 and which responds to the modulation only on the DC voltage in line 15.

The invention might be better understood by the use of specific figures. For example, the system 10 is connected to a 40-volt DC source 11 through the voltage regulator 12. Zener circuit 17 is of such a design as to provide the base 16 with a voltage to produce an output of 25 volts to the wire 15. The microphone 29 produces an audio signal which is amplified by the amplifier 30 to provide 5-volt AC at the output which is connected through switch 31 and potentiometer or outgoing volume control 32 to the zener circuit and is impressed on the base of the transistor to modulate the output of the voltage regulator between 20 and 30 volts at the frequency of the audio signal. This is picked up by the speaker 35 at the other end of the wire which is connected to wire 15 just prior to the voltage regulator 22 and will reproduce the audio signal which is impressed on the base 16.

Should a two-way system for communication be desired, a microphone 37 is connected through potentiometer or outgoing volume control 38 to an amplifier 39 to the wire 15 at a point prior to the voltage regulator 22. The amplifier 39 is powered from the output side of the voltage regulator 22 such as 12 volts. A speaker 40 is connected through a nonnally closed contact of the switch 31 to a potentiometer 41, amplifi er 42 for the incoming signal to the other end of the wire 15 before the connection to the output terminal of the voltage regulator 12. This will reproduce any signals produced by the microphone 37 so that two-way communication can be had. The microphone 37 and speaker 35 are usually in close proximity and the potentiometer 38 is adjusted to limit the gain and prevent feedback therebetween.

Variations and modifications may be made within the scope of the invention and portions of the improvements may be used without others.

lclaim:

1. Means for communicating over a single-wire DC circuit, comprising a source of DC of a predetermined voltage, a first voltage controller connected in series with said source and including a transistor having a base terminal and a zener circuit connecting said base terminal to ground, said zener circuit including a zener diode and an impedance in series and controlling said base terminal to produce a desired output DC voltage for said voltage controller at a predetermined value less than the source voltage, a second similar voltage controller series connected at the other end of the wire and having an output at a lower voltage value than the first voltage controller, signal means for producing and impressing a signal voltage on the base of the first voltage controller to vary and modulate the output of said controller in accordance with the impressed signal voltage, and means connecting a receiver to the other end of the wire prior to said second voltage controller to reproduce the signal.

2. The invention as defined in claim 1 wherein there is a signal means producing a second signal voltage, means connecting said second signal voltage through an amplifier to the wire prior to said second voltage controller to impress said signal on the wire, and means connecting a receiver to the wire between said first connection and said first controller to reproduce the second signal whereby two-way communication is obtained.

3. The invention as defined in claim 1 wherein the signal means includes a microphone and produces an audio signal of predetennined voltage to modulate said output in accordance with the frequency of said audio signal.

4. The invention as defined in claim 2 wherein the signal means comprises a microphone to produce an audio signal.

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Claims (4)

1. Means for communicating over a single-wire DC circuit, comprising a source of DC of a predetermined voltage, a first voltage controller connected in series with said source and including a transistor having a base terminal and a zener circuit connecting said base terminal to ground, said zener circuit including a zener diode and an impedance in series and controlling said base terminal to produce a desired output DC voltage for said voltage controller at a predetermined value less than the source voltage, a second similar voltage controller series connected at the other end of the wire and having an output at a lower voltage value than the first voltage controller, signal means for producing and impressing a signal voltage On the base of the first voltage controller to vary and modulate the output of said controller in accordance with the impressed signal voltage, and means connecting a receiver to the other end of the wire prior to said second voltage controller to reproduce the signal.

2. The invention as defined in claim 1 wherein there is a signal means producing a second signal voltage, means connecting said second signal voltage through an amplifier to the wire prior to said second voltage controller to impress said signal on the wire, and means connecting a receiver to the wire between said first connection and said first controller to reproduce the second signal whereby two-way communication is obtained.

3. The invention as defined in claim 1 wherein the signal means includes a microphone and produces an audio signal of predetermined voltage to modulate said output in accordance with the frequency of said audio signal.

4. The invention as defined in claim 2 wherein the signal means comprises a microphone to produce an audio signal.

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