LCD Hook-on digital ammeter
First Claim
1. A hook-on digital ammeter comprisingan annular magnetic core interrupted at at least one location such that the core material at opposite sides of the interruption is sufficiently separable to allow passage of a conductor through the interruption;
- a secondary winding wound on said core, said secondary winding being tapped at a plurality of points thereon;
liquid crystal display means comprising a plurality of display segments having a common connection; and
circuit means coupling a separate one of said taps;
respectively, to a separate segment of said liquid crystal display means, respectively, said common connection being connected to one end of said secondary winding such that the optically response state of each segment of said liquid crystal display means is directly determined by the amplitude of AC voltage across said secondary winding.
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Accused Products
Abstract
A low cost hook-on ammeter for consumer use includes a split core to be clipped around a conductor. Secondary turns on the core actuate a liquid crystal digital display to indicate alternating current amplitude in the conductor. The liquid crystal display segments may be connected to individual taps on the secondary winding, or to taps on a resistive divider network connected across the entire secondary winding. As current in the conductor increases, secondary voltage increases, turning on an increasing number of segments of the liquid crystal display accordingly.
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Citations
8 Claims
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1. A hook-on digital ammeter comprising
an annular magnetic core interrupted at at least one location such that the core material at opposite sides of the interruption is sufficiently separable to allow passage of a conductor through the interruption; -
a secondary winding wound on said core, said secondary winding being tapped at a plurality of points thereon; liquid crystal display means comprising a plurality of display segments having a common connection; and circuit means coupling a separate one of said taps;
respectively, to a separate segment of said liquid crystal display means, respectively, said common connection being connected to one end of said secondary winding such that the optically response state of each segment of said liquid crystal display means is directly determined by the amplitude of AC voltage across said secondary winding. - View Dependent Claims (2, 3, 4)
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5. A digital ammeter for measuring alternating current in a conductor, said ammeter comprising:
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an annular magnetic core encircling said conductor carrying alternating current; a secondary winding wound on said core, said secondary winding being tapped at a plurality of points thereon; a liquid crystal display means comprising a plurality of display segments having a common connection; and circuit means coupling a separate one of said taps, respectively, to a separate segment of said liquid crystal display means, respectively, said common connection being connected to one end of said secondary winding such that the optically responsive state of each segment of said liquid crystal display means is directly determined by the amplitude of AC voltage across said secondary winding. - View Dependent Claims (6, 7, 8)
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Specification