Nonadjusting battery life detector
AssigneeKabushiki Kaisha Daini Seikosha
InventorSatoshi Arai
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Abstract
A battery life detector operates by sensing battery voltage. The detector consists of a pair of series combinations of a constant voltage source and a constant current source which are connected to a terminal to which a battery voltage is applied. The constant voltage source outputs are connected to respective inputs of a differential amplifier.
Claims4
Nonadjusting battery life detector characterized in that a first constant voltage source for generating a constant voltage relative to the ground is connected to a battery in series through a first constant current source, a second constant voltage source for generating a constant voltage is connected to the battery in series through a second constant current source, and the constant output voltages from the first and second constant voltage sources are supplied to the two input terminals of a differential amplifier, respectively.
A battery life detector, comprising:
- a differential amplifier having a non-inverting input and an inverting input;
- a terminal for connection, in use, to a battery for receiving a battery voltage to be detected;
- a first constant voltage source having an output terminal connected to the non-inverting input of said differential amplifier for applying a constant voltage to the differential amplifier non-inverting input;
- a first constant current source connected in series with said first constant voltage source for applying a constant current to said first constant voltage source;
- a second constant voltage source having an output terminal connected to the inverting input of said differential amplifier for applying a constant voltage to the differential amplifier inverting input;
- a second constant current source connected in series with said second constant voltage source for applying a constant current to said second constant voltage source;
- and
- means for intermittently connecting the series combination of said first constant voltage source and said first constant current source to said terminal and for intermittently connecting the series combination of said second constant voltage source and said second constant current source to said terminal thereby to operate the battery detector circuit in a sampling operating mode.
Dependencies are inferred from the claim text.