Method and apparatus for deriving power consumption information from the angular motion of a rotating disk in a watt hour meter

An apparatus for recording information about the angular motion of a rotatable disk disposed in a first structure, a first side of the disk having regions with differing reflective properties with respect to electromagnetic energy, the apparatus comprising:

• a housing mounted on the first structure adjacent the first side of the disk;
• first means mounted on the housing for emitting a first sequence of electromagnetic energy pulses in a first direction toward the disk;
• second means mounted on the housing for emitting a second sequence of electromagnetic energy pulses in a second direction toward the disk, the first and second directions being such that the first and second sequences of electromagnetic energy pulses reflect from the first side of the disk in different areas, the areas being separated in the direction of rotation of the disk;
• photosensitive means mounted on the housing so that the photosensitive means can receive the reflected electromagnetic energy pulses from both the first and second emitting means at a single point, the photosensitive means being for generating a signal in response to the received electromagnetic energy pulses, the signal having characteristics dependent upon the reflective properties of the regions from which the electromagnetic energy pulses are reflected;
• and
• a controller coupled to the photosensitive means for processing the signal to determine the number of rotations of the disk, and the direction of rotation of the disk, the controller also being for synchronizing the first and second sequences of electromagnetic energy pulses such that each electromagnetic energy pulse from the first emitting means is followed by an electromagnetic energy pulse from the second emitting means.

An apparatus for recording information about the angular motion of a rotatable disk disposed in a first structure, the-disk having at least one aperture through which electromagnetic energy is transmitted, the apparatus comprising:

• first means for emitting a first sequence of electromagnetic energy pulses, the first emitting means being mounted on the first structure adjacent a first side of the disk;
• second means for emitting a second sequence of electromagnetic energy pulses, the second emitting means being mounted on the first structure adjacent the first side of the disk and separated from the first emitting means in the direction of rotation of the disk;
• photosensitive means mounted on the first structure on the opposite side of the disk from the first and second emitting means so that the photosensitive means can receive the electromagnetic energy pulses transmitted through the at least one aperture from both the first and second emitting means at a single point, the photosensitive means being for generating a signal in response to the received electromagnetic energy;
• and
• a controller coupled to the photosensitive means for processing the signal to determine the number of rotations of the disk, and the direction of rotation of the disk, the controller also being for synchronizing the first and second sequences of electromagnetic energy pulses such that each electromagnetic energy pulse from the first emitting means is followed by an electromagnetic energy pulse from the second emitting means.

A method for deriving information about the rotation of a rotatable disk, a first side of the disk having regions with differing reflective properties with respect to electromagnetic energy, the method comprising the steps of:

• (1) reflecting a first sequence of electromagnetic energy pulses from a first emitting means from the first side of the disk;
• (2) receiving the reflected first sequence of electromagnetic energy pulses from the first emitting means at a first point with a photosensitive means;
• (3) generating a first signal pulse with the photosensitive means corresponding to the received first sequence of electromagnetic energy pulses from the first emitting means;
• (4) reflecting a second sequence of electromagnetic energy pulses from a second emitting means from the first side of the disk, the second sequence being synchronized with the first sequence such the each electromagnetic energy pulse from the first emitting means is followed by an electromagnetic energy pulse from the second emitting means;
• (5) receiving the reflected second sequence of electromagnetic energy pulses from the second emitting means at the first point with the photosensitive means;
• (6) generating a second signal pulse with the photosensitive means corresponding to the received second sequence of electromagnetic energy pulses from the second emitting means;
• (7) repeating steps (1) through (6), thereby generating a pulse train comprising the first and second signal pulses;
• and
• (8) processing the pulse train to determine the number of rotations of the disk, and the direction of rotation of the disk.

A watt-hour meter having a first structure, comprising:

• a rotatable disk disposed within the first structure, the disk having regions with differing properties with respect to electromagnetic energy;
• first means for emitting a first sequence of electromagnetic energy pulses in a first direction toward the disk, the first emitting means being mounted on the first structure adjacent a first side of the disk;
• second means for emitting a second sequence of electromagnetic energy pulses in a second direction toward the disk, the second emitting means being mounted on the first structure adjacent the first side of the disk, the first and second directions being such that the first and second sequences of electromagnetic energy pulses reflect from the first side of the disk in different areas, the areas being separated in the direction of rotation of the disk;
• photosensitive means mounted on the first structure so that the photosensitive means can receive the electromagnetic energy pulses from both the first and second emitting means at a single point, the photosensitive means being for generating a signal in response to the received electromagnetic energy pulses;
• and
• a controller coupled to the photosensitive means for processing the signal to determine the number of rotations of the disk, and the direction of rotation of the disk, the controller also being for synchronizing the first and second sequences of electromagnetic energy pulses such that each electromagnetic energy pulse from the first emitting means is followed by an electromagnetic energy pulse from the second emitting means.