Multimeter with tone indication
First Claim
1. In a meter for measuring an electrical quantity, said meter having a display means and a range selection means defining a plurality of values for said display means for measuring ranges of values of said electrical quantity, the improvement comprising means coupled to and operative with said range selection means for setting a selected reference value of said electrical quantity, means for comparing the value of said measured electrical quantity with said selected reference value of said electrical quantity and means for generating an audible signal in response in said comparison.
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Accused Products
Abstract
A digital multimeter having a tone generating circuitry and operable in a tone mode of operation for providing an audible indication when a measured electrical characteristic has a predetermined relationship with a reference value. The audible indication may be provided when a voltage level exceeds a preselectable limit, such as 1 or 2 volts. Predetermined limits for resistance values may also be selected for actuation of the audible tone. The device may be utilized as a conventional multimeter when the tone mode is non-operative.
43 Citations
10 Claims
- 1. In a meter for measuring an electrical quantity, said meter having a display means and a range selection means defining a plurality of values for said display means for measuring ranges of values of said electrical quantity, the improvement comprising means coupled to and operative with said range selection means for setting a selected reference value of said electrical quantity, means for comparing the value of said measured electrical quantity with said selected reference value of said electrical quantity and means for generating an audible signal in response in said comparison.
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2. In a meter for measuring an electrical quantity, said meter having a display means and a range selection means defining a plurality of values for said display means for measuring ranges of values of said electrical quantity, the improvement comprising means coupled to and operative with said range selection means for setting a selected reference value of said electrical quantity, means for comparing the measured electrical quantity with said selected reference value of said electrical quanitity, means operating said meter selectively in first and second comparison modes, and means responsive to said comparison means and said reference selecting means for generating an audible signal when said measured value is above said selected reference value and said meter is in said first comparison mode and for generating the audible signal when said measured value is below said selected reference value and said meter is in said second comparison mode.
Specification