Electronic ampere-hour meter
AssigneeInstitutul de Cercetari Pentru Industria Electrotehnica
InventorsIonel Radu, Florin T. Tanasescu
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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.
Claims4
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.
Dependencies are inferred from the claim text.