Remote monitoring induction telemetering system

• US 4,608,563 A
• Filed: 05/03/1982
• Issued: 08/26/1986
• Est. Priority Date: 05/03/1982
• Status: Expired due to Fees

• Current Assignee: General Services Engineering Incorporated
• Original Assignee: General Services Engineering Incorporated
• Inventors: Hoffman, Gary R.
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Heim, Michael F.
• Application Number:
  US06/374,626
• Time in Patent Office: 1,576 Days
• Field of Search: 324/113, 324/137, 324/157, 324/207, 324/208, 331/65, 340/870.02, 340/870.03, 340/870.05, 340/870.31, 340/870.32, 340/870.39, 340/870.19, 340/870.20, 340/870.25, 310/111
• US Class Current: 340/870.02
• CPC Class Codes: G01R 11/16 Adaptations of counters to electricity meters
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G06M 1/274 using magnetic means; using Hall-effect devices

Abstract

A wheel is mounted on a rotating shaft and cooperates with at least one pair of inductors fixedly mounted in juxtaposition to the wheel. The wheel has at least one opening formed therein for generating a signal whenever the opening in the wheel is substantially aligned circumferentially with the pair of inductors. An electronic control circuit, responsive to the signal, actuates a remote meter for providing a remote indication of the shaft position.

In a preferred embodiment, this improved sensing means is applied to the remote reading of a conventional household electric meter. Two pair of inductors are provided for cooperation with five equiangularly-spaced closed slots formed in the wheel, thereby providing ten signals (or counts) for each complete revolution of the wheel. The wheel is mounted on the shaft of the unit decade dial in the meter. The remote meter comprises a digital counter, responsive to the pulse generated by the electronic control circuit, for providing a remote digital read-out of the accumulated kilowatt hours on the meter.

Claims

1. In an apparatus having a rotating shaft, a means for monitoring the position of the shaft, comprising, in combination, a wheel means mounted on the shaft for conjoint rotation therewith, the wheel means having at least one closed opening therein, at least one pair of inductors fixedly mounted in juxtaposition to the wheel means, means for energizing one inductor of the pair of inductors to produce current flow around at least one edge of the opening, means responsive to a substantial circumferential alignment between the closed opening and the pair of inductors to generate a signal in the other inductor of said pair of inductors as a result of a magnetic field produced by the current flow around the at least one edge of the opening, and means responsive to the signal for providing an indication of the position of the shaft, wherein said at least one pair of inductors comprises two pairs of inductors mounted adjacent to one side of the wheel means along respective axes radially of the axis of rotation of the shaft, the inductor pairs being alternately activated relative to one another, and wherein the at least one opening comprises five equiangularly spaced closed slots formed in the wheel means, whereby a total to ten signals are generated for each complete revolution of the wheel means.

2. The combination of claim 1, wherein the respective radial axes of the two pairs of inductors are so arranged that whenever one pair of inductors is aligned circumferentially with one of the closed slots, the other pair of inductors will be located substantially equidistantly between a pair of the closed slots.

3. The combustion of claim 1, futher including means for generating a signal only when the wheel means is being rotated in its intended forward direction, thereby assuring that erroneous signals will not be generated due to free-play or backlash in the wheel means.

4. In an apparatus having a rotating shaft, a means for monitoring the position of the shaft, comprising, in combination, a wheel mounted on the shaft for conjoint rotation therewith, the wheel having five radially-projecting closed slots formed therein, the slots being equiangularly spaced around the circumference of the wheel, two pairs of inductors fixedly mounted in juxtaposition to the wheel, each inductor pair comprising a "sending" inductor and a "receiving" inductor, the inductors in each pair being spaced apart from one another along a radial axis, the respective axes of the inductor pairs being so arranged that whenever one inductor pair is aligned circumferentially with one of the closed slots, the other inductor pair will be located substantially equidistantly between a pair of slots, means for alternately energizing the sending inductors in the respective pairs of inductors, sequentially, whereby the inductors in a respective pair of inductors will be coupled together whenever one of the slots in the wheel is substantially aligned circumferentially with one of the inductor pairs, thereby generating a total of ten signals for each complete revolution of the wheel, and means including a remote counter responsive to said signals.

5. The combination of claim 4, wherein the means for alternately energizing the sending inductors in the respective pairs of inductors comprises a bi-stable flip-flop circuit, and a pair of oscillator drive switches, one for each of the inductor pairs, connected to the output of the bi-stable flip-flop circuit.

6. The combination of claim 5, wherein the means responsive to said coupling for providing an indication of the shaft position, comprises an oscillator connected to the outputs of the respective receiving inductors, a detector connected to the output of the oscillator, a Schmitt trigger connected to the output of the detector, a one-shot circuit connected to the output of the Schmitt trigger, a one-shot pulse generator connected to the output of the one-shot circuit, the output of the one shot circuit also being connected to the input of the bi-stable flip-flop circuit, and means for driving the remote counter from the pulse generator.

7. The combination of claim 6, wherein said last-named driving means comprises an AND gate and a driver between the pulse generator and the remote counter.

8. The combination of claim 7, further including a regulated power supply comprising a transformer, a full-wave bridge rectifier connected to the output of the transformer, means including a regulator connected to the output of the rectifier for providing a regulated supply voltage to various circuit points, a comparator, means for connecting the input of the comparator to the output of the regulator and to the output of the rectifier, and the output of the comparator being fed to the input of the AND gate.

9. In an apparatus having a rotating shaft, a means for monitoring the position of the shaft, comprising, in combination, a wheel mounted on the shaft for conjoint rotation therewith, the wheel having five radially-projecting closed slots formed therein, the slots being equiangularly spaced around the circumference of the wheel, two pairs of inductors fixedly mounted in juxtaposition to the wheel, each inductor pair comprising a "sending" inductor and a "receiving" inductor, the inductors in each pair being spaced apart from one another along a radial axis, the respective axes of the inductor pairs being so arranged that whenever one of the inductor pairs is aligned circumferentially with one of the closed slots, the other inductor pair is substantially equidistant between a pair of slots, means for alternately energizing the sending inductors in the respective pairs of inductors, said means including a bi-stable flip-flop circuit whose output is connected to a pair of oscillator drive switches, one for each of the sending inductors, whereby a respective pair of inductors will be coupled together whenever one of the slots in the wheel is substantially aligned circumferentially with one of the inductor pairs, thereby generating a total of ten signals for each complete revolution of the wheel, means responsive to said signals for providing an indication of the shaft position, said last-named means including an oscillator connected to the output of the respective receiving inductors, a detector connected to the output of the oscillator, a Schmitt trigger connected to the output of the detector, a one-shot circuit connected to the output of the Schmitt trigger, and a one-shot pulse generator connected to the output of the one-shot circuit, the output of the one-shot circuit also being connected to the input of the bi-stable flip-flop circuit, a remote counter providing a digital indication of the signals, and means for driving the counter from the pulse generator.

10. The combustion of claim 9, wherein the apparatus comprises an electric meter, and wherein the wheel is mounted on the shaft of the unit decade dial of the meter.

11. The combustion of claim 9, wherein the oscillator comprises a transistor oscillator, and wherein capacitor means are provided to phase establish the transistor oscillator.

12. In a means for sensing the position of a rotating wheel, the combination of a pair of inductors, coupling means carried by said wheel for coupling the inductors to one another at a predetermined position of the wheel, first capacitor means for resonating the inductors, respectively, oscillator means responsive to signals passed by said coupling means between the inductors, and second capacitor means connected between output and input of the oscillator means for establishing phase of the ouput from the oscillator means in conjunction with phase shift provided by the first capacitor means, the coupling means and the inductors of the pair of inductors.

13. The combination of claim 12, wherein the oscillator means includes a transistor having a base, emitter and collector, and wherein the second capacitor means comprises a capacitor connected between the base and the collector.

14. Means for monitoring the position of a rotating shaft, comprising, in combination, sensing means fixedly mounted in juxtaposition to the shaft, means carried by the shaft and cooperating with the sensing means to generate a signal therein at a predetermined position of the shaft, oscillator means responsive to the signal from the sensing means for generating an oscillator burst, detection means coupled to the oscillator burst, a Schmitt trigger coupled to the output of the detection means for generating a negative pulse, a one-shot integrated circuit responsive to the negative pulse for generating a positive pulse, a one-shot pulse generator responsive to the positive pulse for generating a pulse of a predetermined duration, and means including a remote digital counter responsive to the pulse from the one-shot pulse generator for providing a remote digital read-out of the shaft position.

15. Means for monitoring the position of a rotating shaft, comprising, in combination, sensing means fixedly mounted in juxtaposition to the shaft, means carried by the shaft and cooperating with the sensing means to generate a signal therein at a predetermined position of the shaft, oscillator means responsive to the signal from the sensing means for generating an oscialltor burst, detection means coupled to receive the oscillator burst, a Schmitt trigger coupled to the output of the detection means for generating a negative pulse, a one-shot integrated circuit responsive to the negative pulse for generating a positive pulse, a one-shot pulse generator responsive to the positive pulse for generating a pulse of a predetermined duration, and means including a remote digital counter responsive to the pulse from the one-shot pulse generator for providing a remote digital read-out of the shaft position, wherein the sensing means comprises respective pairs of sensory elements, wherein the combination further includes a pair of oscillator drive switches for sequentially energizing a respective sensory element in the respective pairs, and a bi-stable flip-flop circuit for energizing the oscillator drive switches, and wherein the output of the one-shot integrated circuit is also fed to the input of the bi-stable flip-flop circuit.

16. In an apparatus having a rotating shaft, a means for monitoring the position of the shaft, comprising, in combination, a wheel means mounted on the shaft for conjoint rotation therewith, the wheel means having at least one opening therein, at least two pairs of inductors fixedly mounted in justaposition to the wheel means, means for energizing one of the inductors, means responsive to a substantial circumferential alignment between the opening and the pair of inductors to generate a signal in the other inductor, and means responsive to the signal for providing an indication of the position of the shaft, wherein the two pairs of inductors are mounted adjacent to one side of the wheel means along respective axes radially of the axis of rotation of the shaft, the inductor pairs being alternately activated relative to one another, and wherein the at least one opening comprises five equiangularly spaced closed slots formed in the wheel means, whereby a total of ten signals are generated for each complete revolution of the wheel means.

17. The combination of claim 16, wherein the respective radial axes of the two pairs of inductors are so arranged that whenever one pair of inductors is aligned circumferentially with one of the closed slots, the other pair of inductors will be located substantially equidistantly between a pair of the closed slots.

18. The combination of claim 16, further including means for generating a signal only when the wheel means is being rotated in its intended forward direction, thereby assuring that erroneous signals will not be generated due to free-play or backlash in the wheel means.

19. In a meter, an improved means for monitoring the position of a rotating shaft, comprising, in combination, sensing means fixedly mounted in juxtaposition to the shaft, inductive pick-up means carried by the shaft and cooperating with the sensing means to generate a signal therein at a predetermined position of the shaft, oscillator means responsive to the signal from the sensing means for providing an output, detection means coupled to the oscillator output, a trigger circuit coupled to the output of the detection means for generating a pulse, a one-shot integrated circuit responsive to the pulse from the detection means for generating a pulse, a one-shot pulse generator responsive to the pulse from the one-shot integrated circuit for generating a pulse of a predetermined duration, and means including a remote digital counter responsive to the pulse from the one-shot pulse generator for providing a remote digital read-out of the shaft position in the meter.