Electronic ampere-hour meter
First Claim
1. An electronic ampere-hour meter for measuring current consumption in a load powered by a source of direct current, comprising:
- a resistor connected across the source in series with the load for developing a voltage drop proportional to load current;
a multivibrator generating a train of constant-amplitude first pulses;
a modulator in series with said multivibrator having input terminals connected across said resistor for changing the amplitudes of said first pulses in accordance with said voltage drop;
a demodulator connected to said modulator for converting the amplitude-modulated first pulses into a unipolar voltage proportional to said voltage drop;
sampling means connected to said demodulator for deriving from said unipolar voltage a series of second pulses whose recurrence frequency varies with the level of said unipolar voltage;
numerical display means connected to said sampling means for visually indicating a count of said second pulses representative of the electric energy consumed by the load; and
a supply network for circuit components including said multivibrator, said demodulator, said sampling means and said display means, said network being connected across the load.
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Abstract
An amp-hour meter for a load driven by direct current, such as an electric vehicle, comprises a modulator connected across a resistor in series with the load for amplitude-modulating a pulse train from a multivibrator translated by a demodulator into a unipolar voltage varying with the load current. A sampler converts this voltage into a train of output pulses, generated at a rate proportional to the voltage level, whose count is numerically displayed as a measure of current consumption. The multivibrator, the demodulator, an intervening amplifier, the sampler and the display unit are serially energized with stabilized voltage and reduced current via a supply network connected across the load, this network including a ballast lamp in series with a Zener diode.
43 Citations
4 Claims
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1. An electronic ampere-hour meter for measuring current consumption in a load powered by a source of direct current, comprising:
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a resistor connected across the source in series with the load for developing a voltage drop proportional to load current; a multivibrator generating a train of constant-amplitude first pulses; a modulator in series with said multivibrator having input terminals connected across said resistor for changing the amplitudes of said first pulses in accordance with said voltage drop; a demodulator connected to said modulator for converting the amplitude-modulated first pulses into a unipolar voltage proportional to said voltage drop; sampling means connected to said demodulator for deriving from said unipolar voltage a series of second pulses whose recurrence frequency varies with the level of said unipolar voltage; numerical display means connected to said sampling means for visually indicating a count of said second pulses representative of the electric energy consumed by the load; and a supply network for circuit components including said multivibrator, said demodulator, said sampling means and said display means, said network being connected across the load. - View Dependent Claims (2, 3, 4)
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Specification
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- Resources
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Current AssigneeInstitutul de Cercetari Pentru Industria Electrotehnica - ICPE
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Original AssigneeInstitutul de Cercetari Pentru Industria Electrotehnica - ICPE
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InventorsTanasescu, Florin T., Radu, Ionel
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Primary Examiner(s)Krawczewicz, Stanley T.
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Application NumberUS05/967,850Time in Patent Office872 DaysField of Search324/142, 324/118, 324/120, 324/111, 324/428, 324/427US Class Current324/142CPC Class CodesG01R 21/127 by using pulse modulation G...
