Showing papers on "State of charge published in 1981"
Patent•
16 Nov 1981
TL;DR: In this paper, the system includes a digital integrator having a plurality of digital stages operable to store a numerical value in binary digital form which is indicative of state of charge, and a switching circuit is provided for generating a series of voltage pulses on a single output line with each pulse corresponding in length to the binary digital value stored in the integrator to provide a time based resultant indication of the stored binary digital values.
Abstract: The system includes a digital integrator having a plurality of digital stages operable to store a numerical value in binary digital form which is indicative of state of charge. A switching circuit is provided for generating a series of voltage pulses on a single output line with each pulse corresponding in length to the binary digital value stored in the integrator to provide a time based resultant indication of the stored binary digital value. A filtering means is included to provide a substantially smooth analog output voltage having an amplitude corresponding to the summation of the pulses. The system preferably includes a delayed high voltage reset feature to set the integrator to a full charge state in response to voltage levels accompanying charging of the battery.
65 citations
Patent•
23 Jul 1981
TL;DR: In this article, the state of charge of a battery during a quiescent interval with substantially no current flow through the battery was determined by determining the quiescence time interval since the last substantial current flow, and then taking a rapid measurement of the battery terminal voltage.
Abstract: State of charge is determined for a battery during a quiescent interval with substantially no current flow through the battery by determining the quiescent time interval since the last substantial current flow through the battery, taking a rapid measurement of the battery terminal voltage, and relating the combination of these two measurements to known battery open circuit voltage recovery characteristics.
57 citations
Patent•
23 Jul 1981
TL;DR: In this article, the measurement of the state of charge of a battery used to operate a voltage converter and storage capacitor circuit for an electronic flash unit, built into a camera, gives a reliable automatic indication shortly after the circuit is switched on.
Abstract: The arrangement is for the measurement of the state of charge of a battery used to operate a Voltage converter and storage capacitor circuit for an electronic flash unit, esp. one built into a camera, gives a reliable automatic indication shortly after the circuit is switched on. The time taken for the storage capacitor (7) to charge up to a defined voltage force is compared with a reference time from a clock circuit (2). An electrical indicator (10) is controlled according to the result of the comparison. The time circuit (2) is triggered when the main switch (1) is turned on. After a reference time it triggers a bistable (5) when the latter voltage has been attained. The bistable, a D-type flip-flop, drives the indicator. It can also control the camera shutter release.
2 citations
30 Dec 1981
TL;DR: In this article, the index of refraction and critical angle were used to determine the state of charge of a lead-acid battery, and the critical angle of the battery was calculated by an optic device.
Abstract: An optic device utilizes the index of refraction and critical angle to determine the state of charge of a lead-acid battery.
2 citations
15 Jan 1981
TL;DR: In this article, a positive displacement gas flow meter was used to measure gassing rates and oxygen fractions, which proved to be both simple and highly accurate, and the measurements were used to optimize charge procedures.
Abstract: Charge efficiencies were determined by measurements made under widely differing conditions of temperature, charge procedure, and battery age. The measurements were used to optimize charge procedures and to evaluate the concept of a modified, coulometric state of charge indicator. Charge efficiency determinations were made by measuring gassing rates and oxygen fractions. A novel, positive displacement gas flow meter which proved to be both simple and highly accurate is described and illustrated.
1 citations