Direction sensitive opto-electronic pulse initiator for electrical meters

Claim 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.