An electronic circuit breaker comprising: an input connected to an electric DC power supply; an output connected to a load; the input connected to the output via a switch, said switch is controlled via a switch control line between an “ON”-state and an “OFF”-state; a switch driver connected to the switch control line, said switch driver configured to control the switch; and a switch protection, a voltage detection branch configured to output a first electric potential indicative of the electrical potential difference between the input and the output; a comparator circuit configured to compare the first electrical potential with a first threshold voltage, said first threshold voltage is indicative of an over-current level flowing through the switch; and a gate controller connected to the switch disable line and configured to disable the switch by connecting the switch control line to a potential which causes the switch to enter the “OFF”-state.

A method for detecting arc faults when charging electric battery systems or lead acid batteries, which are electrically connected in series to form a string which is supplied via a DC voltage converter. A first value corresponding to an electric voltage applied to the string and a second value corresponding to an electric current flowing through the string are generated. As a first condition, it is checked whether the first value changes by more than a first limit value within a first time window. As the second condition, it is checked whether the second value changes by more than a second limit value within a second time window. An arc is detected if the first condition and the second condition are met within a third time window. Provided also is a method for manufacturing electric battery systems, in particular lead acid batteries, as well as to a cut-off device.

A secondary battery protection circuit for a secondary battery includes: a reference voltage circuit configured to generate a reference voltage by using a depletion-type transistor and a transistor unit of enhancement type connected in series with the depletion-type transistor; a voltage divider configured to output a detection voltage obtained by dividing a power source voltage of the secondary battery; a detection circuit configured to detect an abnormal state of the secondary battery based on the reference voltage and the detection voltage; a first adjustment circuit configured to adjust a size ratio of the depletion-type transistor to the transistor unit based on threshold voltages of the depletion-type transistor and the transistor unit; and a second adjustment circuit configured to adjust the detection voltage based on the reference voltage after adjusting the size ratio.

A secondary battery protection circuit for a secondary battery includes: a reference voltage circuit configured to generate a reference voltage by using a depletion-type transistor and a transistor unit of enhancement type connected in series with the depletion-type transistor; a voltage divider configured to output a detection voltage obtained by dividing a power source voltage of the secondary battery; a detection circuit configured to detect an abnormal state of the secondary battery based on the reference voltage and the detection voltage; a first adjustment circuit configured to adjust a size ratio of the depletion-type transistor to the transistor unit based on threshold voltages of the depletion-type transistor and the transistor unit; and a second adjustment circuit configured to adjust the detection voltage based on the reference voltage after adjusting the size ratio.

A battery voltage equalization device 1 includes: a transformer T including a primary winding T1 into which the output voltage of a battery pack BP is inputted and a plurality of secondary windings T2 corresponding to each of batteries B; a conversion circuit 2 that converts an AC voltage outputted by the secondary windings T2 to a DC voltage; a cutoff circuit 3 provided to cut off a conductive pathway from the conversion circuit 2 to the batteries B; and a control unit 5 that controls the energization of the primary winding T1, wherein the cutoff circuit 3 includes a first switch SW1 and the second switch SW2 which are provided in series on the conductive pathway and which are opened or closed by the control unit, a first body diode Db1 and a second body diode Db2 of which the same terminals are connected to each other and which are respectively connected in parallel with the switches, and a surge suppression resistor Rss connected in parallel with the first body diode Db 1 or the second body diode Db2 for which the direction of charging current to the batteries B is the forward direction.

A battery voltage equalization device 1 includes: a transformer T including a primary winding T1 into which the output voltage of a battery pack BP is inputted and a plurality of secondary windings T2 corresponding to each of batteries B; a conversion circuit 2 that converts an AC voltage outputted by the secondary windings T2 to a DC voltage; a cutoff circuit 3 provided to cut off a conductive pathway from the conversion circuit 2 to the batteries B; and a control unit 5 that controls the energization of the primary winding T1, wherein the cutoff circuit 3 includes a first switch SW1 and the second switch SW2 which are provided in series on the conductive pathway and which are opened or closed by the control unit, a first body diode Db1 and a second body diode Db2 of which the same terminals are connected to each other and which are respectively connected in parallel with the switches, and a surge suppression resistor Rss connected in parallel with the first body diode Db 1 or the second body diode Db2 for which the direction of charging current to the batteries B is the forward direction.

In a power supply system, a first system includes a first power supply connected to a first load. A second system includes a second power supply connected to a second load. A connection path connects the systems. An intersystem switch is provided on the connection path. A control apparatus sets the intersystem switch to a closed state and sets a voltage of the first power supply to be higher than a voltage of the second power supply to be a first state in which power supply is performed from the first power supply to the loads. In response to a reverse-direction current from the second system to the first system flowing to the connection path in the first state, the control apparatus sets the intersystem switch to an open state to be a second state in which power supply is performed from the second power supply to the second load.

When a module controller of a battery system detects an abnormality of a battery module, the module controller selects the battery module without stopping the battery module. After that, the module controller compares a current value of a current supplied to a load, with a total value of rated currents of all battery modules that are normal and that are supplying power to the load. When the current value of the current supplied to the load is greater than the total value of the rated currents of the battery modules, the module controller performs a control to stop all the battery modules. When the current value of the current supplied to the load is less than or equal to the total value of the rated currents of all the battery modules that are supplying power to the load, the module controller performs a control to stop the abnormal battery module and not to stop the normal battery modules.

A current measurement apparatus configured to quickly block current. The current measurement apparatus includes a first terminal, a second terminal, a resistor interposed in a separated space between the first terminal and the second terminal; a circuit board, a control unit mounted on the circuit board and configured to measure a current flowing in the resistor by using a voltage value between the first terminal and the second terminal and a resistance value of the resistor, and a cutting unit located above or below the resistor and configured to cut the resistor according to a control signal of the control unit.

A current measurement apparatus configured to quickly block current. The current measurement apparatus includes a first terminal, a second terminal, a resistor interposed in a separated space between the first terminal and the second terminal; a circuit board, a control unit mounted on the circuit board and configured to measure a current flowing in the resistor by using a voltage value between the first terminal and the second terminal and a resistance value of the resistor, and a cutting unit located above or below the resistor and configured to cut the resistor according to a control signal of the control unit.