Direction sensitive opto-electronic pulse initiator for electrical meters

• US 4,034,292 A
• Filed: 02/18/1976
• Issued: 07/05/1977
• Est. Priority Date: 02/18/1976
• Status: Expired due to Term

• Current Assignee: ABB Power T&D Limited (ABB Limited)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: McClelland, Theodore M. III
• Primary Examiner(s): Strecker, Gerard R.
• Application Number:
  US05/658,951
• Time in Patent Office: 503 Days
• Field of Search: 324/96, 324/97, 324/137, 324/157, 324/103 R, 250/233, 250/231 SE, 360/41, 340/201 P, 340/204, 340/206
• US Class Current: 324/157
• CPC Class Codes: G01R 11/02 Constructional details
• CPC Class Codes: G01R 11/09 Disc armatures
• CPC Class Codes: G01R 11/36 Induction meters, e.g. Ferraris meters
• CPC Class Codes: G01R 11/66 Circuitry
• CPC Class Codes: G01R 21/00 Arrangements for measuring electric power or power factor G01R7/12 takes precedence

Abstract

An opto-electronic pulse initiator for producing meter data pulses from a meter having a rotating movement. A directionally oriented pattern containing at least two reflective surfaces is driven by the meter movement to sequentially activate first and second optical sensors. The sensors are activated in opposite sequences in response to opposite rotations of the meter movement. A solid state pulse initiating circuit is utilized and includes low power digital integrated circuit elements, including a clocked bistable logic circuit. The optical sensors are connected to the inputs of the bistable logic circuit to produce predetermined mutually opposite binary logic states at the outputs of the bistable circuit, with the logic states corresponding to a given direction of meter movement. Data pulse output channels are controlled by the bistable logic circuit to selectively produce meter data pulses for a predetermined direction of rotation of the meter movement.

Claims

1. A direction sensitive pulse initiator for an electrical meter having an electro-responsive meter movement including a rotating member which rotates in opposite directions and at a rate corresponding to the direction and amount of an electric power quantity to be measured by the electrical meter, said pulse initiator comprising:

a light reflecting pattern including first and second circularly arcuate surfaces disposed on the rotating member, said first of the reflecting surfaces extending along a first circular axis between first and second ends thereof, and said second of the reflecting surfaces extending along a second circular axis between first and second ends which are arcuately staggered relative to said first and second ends of said first surface and being positioned along a second arc, said second circular axis being concentric with said first circular axis and having a radius which is greater than the radius of the first circular axis;

first and second optical sensors mounted on said meter in alignment with said first and second circular axes, respectively, so as to separately detect the respective first and second reflecting surfaces when positioned adjacent the sensors, said first and second sensors being activated by the adjacent positioning of said first and second surfaces to produce first and second impulses;

said first and second sensors and said first and second relfecting surfaces being arranged with respect to each other such that rotation of the rotating member in one direction causes at least a portion of the first surface to pass adjacent the first sensor before any portion of the second surface passes adjacent the second sensor, and further such that rotation of the rotating member in the opposite direction causes at least a portion of the second surface to pass adjacent the second sensor before any portion of the first surface passes adjacent the first sensor;

a bistable circuit including first and second inputs connected to receive said first and second impulses from the sensors when the reflecting surfaces pass adjacent the sensors, said circuit being connected to establish opposite output states corresponding to said one and opposite directions of rotation and maintaining the associated output state when the direction of rotation remains the same; and

output circuit means for producing output pulses at a rate corresponding to the rate of rotation of said rotating member, said output circuit means including an input connected to the bistable circuit so as to be responsive to the opposite output states, and further including first and second output channels selectively producing said output pulses in accordance with the opposite states of said bistable circuit, said first output channel providing the output pulses corresponding to the power quantity when occurring in one direction, and said second channel providing the output pulses corresponding to the power quantity when occurring in the opposite direction.

2. The initiator of claim 1, wherein the rotating member is a disc electromagnetically driven by magnetic fields of voltage and current coils connected to a power line conducting the power quantity to be measured.

3. The initiator of claim 1, wherein the first and second optical sensors each include photo-emitting, photosensitive, and associated passive circuit elements arranged so that light is reflected from the reflecting surfaces and between the photo-emitting and photosensing elements of each sensor.

4. The initiator of claim 1, wherein the bistable circuit includes a J-K flip-flop and said output circuit means includes first and second switching elements, with the first sensor connected to the J and clocked inputs of the flip-flop and the second sensor connected to the K and clocked inputs of the flip-flop, and with the Q output of the flip-flop being connected to the first switching element which is connected to produce the output pulses in the first channel, and the Q of the flip-flop being connected to the second switching element which is connected to produce the output pulses in the second output channel.

5. The initiator of claim 4, wherein the output circuit means comprises a third optical sensor including a photo-emitting element and a photosensitive element arranged to detect a second pattern of reflective surfaces disposed on the rotating member to reflect light between the photo-emitting and photosensitive elements of said third optical sensor when said rotating member is rotated to develop the output pulses.

6. The initiator of claim 1, wherein the bistable circuit includes the first named and a second J-K flip-flop each having J, K, reset and clocked inputs and Q and Q outputs, said J inputs of the first and second flip-flops being separately connected to the first and second sensors, said clocked inputs connected together and to the first and second sensors, and the bistable circuit further includes first and second logic gates with one input of each logic gate connected to a separate one of the first and second optical sensors and the output of each logic gate connected to a separate reset input of the first and second flip-flops and with a like output of each flip-flop connected to a separate and further input to each logic gate, whereby the outputs of the first and second flip-flops directly produce said output pulses in the first and second output channels, respectively.