Device for monitoring the charging current for a storage battery of accumulators

• US 3,900,785 A
• Filed: 04/09/1974
• Issued: 08/19/1975
• Est. Priority Date: 04/17/1973
• Status: Expired due to Term

• Current Assignee: Andre Alric, Pierre Gentet, Robert Nozeran, Xavier Carlet
• Original Assignee: Andre Alric, Pierre Gentet, Robert Nozeran, Xavier Carlet
• Inventors: Alric, Andre, Carlet, Xavier, Nozeran, Robert, Gentet, Pierre
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/459,335
• Time in Patent Office: 497 Days
• Field of Search: 320/39,40,31,32,43,48 317/36TD,50,51,33SC,33C 340/248,249
• US Class Current: 340/636.13
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3832 without measurement of battery voltage
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/00718 in response to charge current gradient

Abstract

A device for monitoring the charging current for a storage battery of accumulators which will release an alarm when the charging current continues to increase during a set period of time, characterized in that the device contains a means of measuring the current through the storage battery and a further means of transforming the current to a voltage which is placed in a memory system at regular intervals by a switch responding to the recurrent signals from a timing device and is subjected to a comparison with the value of the voltage across the terminals to provide information displayed on a meter when the second value of the voltage exceeds the reference voltage at the instant when a signal is derived from a signal from the time device which signal slightly leads the recurring signals provided by the timing device for the control of the switch, the absence of this information at the instant of the derived signal providing via a logic gate, a signal to reset the meter to zero while the output from the meter provides a control signal for an alarm device.

Claims

1. Device for monitoring the charging current for a storage battery of accumulators, specially for releasing an alarm if the charging current continuously increased during a predetermined time, said device comprising means for deriving an electric voltage proportional to the charging current, a memory system, timer means for generating recurrent timing signals, switching means operatable by each one of said timing signals for storing the instantaneous value of said electric voltage in said memory system, means for comparing the previously stored value of said electric voltage with its actual value, a pulse counter having a counting input, a reset input and an output, means for generating, at a time just preceding the timing signal which follows next said one timing signal, a first or a second pulse according to whether said actual value is superior or inferior to said stored value, means for transmitting said first or second pulse to said counting input or to said reset input of the counter, respectively, and an alarm device connected to the output of said counter.

2. The device as defined in claim 1, characterized in that the means for deriving a voltage proportional to charging current through the storage battery is a resistor mounted in series in the circuit of the storage battery.

3. The device as defined in claim 2, characterized in that the resistor is a shunt of an ammeter.

4. The device as defined in claim 1, characterized in that the said means for comparison of the voltages feeds its results to an AND-gate resulting in the detection of the current.

5. The device as defined in claim 1, characterized in that the device at the threshold of voltage determines the value over which the voltage at the terminals is decided in advance.

6. The device as defined in claim 2, characterized in that the two terminals of the resistor are connected with the inputs to a differential amplifier, one of the terminals being connected to a voltage source determined at the threshold.

7. The device as defined in claim 1, characterized in that the voltage is stored in said memory system by a capacitor and removed therefrom by a unity gain high impedance amplifier, said voltage being compared to the value of the voltage.

8. The device as defined in claim 1, characterized in that the value of the voltage is applied to the input of a differential amplifier with a unity gain when the other input is connected to a voltage source which determines the increase in voltage acceptable at the terminal voltage during the interval of time between storing in memory and the comparison.

9. The device as defined in claim 7, characterized in that the outputs of the unity gain amplifier are mounted in opposition to one of the two inputs to a differential amplifier where the other input is connected to a reference voltage.

10. The device as defined in claim 1, characterized in that the information for comparison and the derived signal are simultaneously supplied to AND-type logic gates where the outputs are respectively supplied to the input of a meter and to a zero reset device.

11. The device as defined in claim 1, characterized in that the timing means consists of an impulse generator associated with a binary counter with staged bistable devices the control pulse for the switching means being obtained by the average of a combination of logic gates associated with the output voltages of the various bistable devices of the counter.

12. The deVice as defined in claim 11, characterized in that the derived pulses are obtained by applying the output voltage of the bistable device with the highest range to a differentiating network, the combination of logic gates providing an unbalanced impulse in advance of the interval of time defined by the first bistable device of a meter, to agree with the waveform of the output voltage controlled by the differentiating network.

13. A device for monitoring the charging current for a storage battery of accumulators which will release an alarm when the charging current continues to increase during a set period of time, said device comprising means for deriving an electric voltage proportional to the charging current, a memory system, timer means for generating recurrent timing signals, switching means operatable by each one of said timing signals for storing the instantaneous value of said electric voltage in said memory system, means for comparing the previously stored value of said electric voltage with its actual value, a pulse counter having a counting input, a reset input and an output, means for generating, at a time just preceding the timing signal which follows next said one timing signal, a first or a second pulse according to whether said actual value is superior or inferior to said stored value, means for transmitting said first or second pulse to said counting input or to said reset input of the counter, respectively, and an alarm device connected to the output of said counter, said means for comparing voltages feeding the result of the said comparison to an AND-gate resulting in the detection of the current, said comparison voltages and the derived signal being simultaneously supplied to AND-logic type gates where the outputs are respectively supplied to the input of the meter and to a zero reset device, said timing means consisting of an impulse generator associated with a binary counter with staged bistable devices the control pulse for the switch being obtained by the average of a combination of logic gates associated with the output voltages of the various bistable devices of the counter, the derived pulses being obtained by applying the output voltage of the bistable device with the highest range to a differentiating network, the combination of logic gates providing an unbalanced impulse in advance of the interval of time defined by the first bistable device of the meter, to agree with the waveform of the output voltage controlled by the differentiating network, a NAND-gate receiving as its input the result of the comparison of the voltages and the result of the detection of the direction of current flow, the output of said gate being connected for entry into the counter, to an input of a NOR-gate while the other input is connected to the differentiating network and, to set the counter to zero, to the input of a NAND-gate where the other input receives an inverse signal to reset to zero, when the output of the NAND-gate is connected to the counter.

14. The device as defined in claim 1, characterized in that the output of the counter is connected to said alarm device by the average maintained by the information supplied by a meter.

15. The device as defined in claim 1, characterized in that the counter is of the binary type and its output is constituted by a NOR-gate where the inputs are connected to the outputs of the bistable devices of the counter which determine the maximum number before being entered into the counter.

16. The device as defined in claim 15, characterized in that the averages of maintenance are constituted by the loop consisting of a NAND-gate, an inverter and a diode, the loop being closed by the input of this NAND-gate and connected to the output of the NOR-gate at the output of the counter, the other input of this NAND-gate receiving the inverse of the signal to reset to zero voluntarily.

17. The device as defined in claim 6, characterized in that the output of the differential amplifier is connectEd to a capacitor which forms said memory system, the impedance of said amplifier being sufficiently weak to allow the time constant determined by the capacitor and said impedance to be inferior to the duration of the closure of said switching means.