Abstract: A plurality of voltage switching circuits 41 are provided in a switching unit 40 to relatively change a reference voltage to plural levels, thus detecting a spontaneous change of the reference voltage. A range of relative change in the reference voltage by the plurality of voltage switching circuits 41 is set to a usage voltage range 81 or 82 as a part of a total voltage range 80 of each of cells 1a to 1d. This eliminates the need to provide voltage switching circuits 41 required to relatively change the reference voltage over the total voltage range of each of the cells 1a to 1d, making it possible to minimize the number of the voltage switching circuits 41 for each of the cells 1a to 1d. Thus, it is possible to prevent the size of a battery pack control apparatus 2 from increasing.

Abstract: Each monitor IC in the apparatus obtains operation power from a block including cells that are the objects to be monitored. The monitor IC includes a consumption-current adjusting circuit that adjusts a consumption current used from the operation power to a target value. In each monitor IC, the consumption current is adjusted to have the target value by the consumption-current adjusting circuit, and thus the consumption currents of the monitor ICs can be equalized, even if a different number of cells are connected to each monitor IC. Accordingly, it is possible to prevent the variation in the consumption currents among the monitor ICs.

Abstract: A first monitor circuit 50 and a second monitor circuit 60 each having an identical configuration are provided in a voltage monitor. A threshold switching section 41 switches a threshold of each of switching units 51 and 61 provided in the respective monitor circuits 50 and 60 to a same value. Each of comparators 53 and 63 compares the threshold with a reference voltage to output a result of the comparison. A fault detecting section 42 compares the respective outputs from the comparators 53 and 63 with each other to detect a characteristic shift of the threshold of each of the monitor circuits 50 and 60.

Abstract: There is disclosed a battery monitoring device including a voltage equalization circuit that equalizes cell voltages of a plurality of battery cells being connected in series and forming a battery pack, and a microcomputer that outputs an instruction signal to instruct the voltage equalization circuit to start an voltage equalizing operation for the battery cells. The microcomputer includes a first timer section that stops the voltage equalizing operation a first predetermined set time after the start of the voltage equalizing operation, and the voltage equalization circuit includes a second timer section that stops the voltage equalizing operation a second predetermined set time after the start of the voltage equalizing operation. This can enhance reliability during the voltage equalizing operation.

Abstract: A battery voltage monitoring device for efficiently equalizing cell voltages of a plurality of battery cells connected in series through a direct charge transfer between mutually distant battery cells. The device includes a charge-transfer circuit configured to perform a direct charge transfer from a first battery cell to a second battery cell that is fifth or higher adjacent to the first battery cell. This can eliminate charge-transfer losses that would occur during sequential charge transfers between adjacent battery cells, which leads to an efficient charge transfer between mutually distant battery cells.

Abstract: The battery pack monitoring apparatus is for monitoring a battery pack constituted of battery blocks connected in series and each including battery cells connected in series. The battery pack monitoring apparatus includes a cell monitoring circuits provided respectively for the battery blocks, and a control circuit. Each of the cell monitoring circuits includes a cell voltage detection circuit to detect cell voltages of the battery cells included in a corresponding one of the battery blocks, and a block voltage detection circuit to detect a block voltage of the corresponding one of the battery blocks. The control circuit is configured to detect states of the battery cells based on the cell voltages and the block voltages transmitted from the respective cell monitoring circuits.

Abstract: A ground fault detector which does not need complicated circuitry and can detect a ground fault with high accuracy in conformity to a capacitance of a common mode capacitor is presented. Upon judging the ground fault on the basis of a threshold for a high-tension power supply system which is electrically isolated and mounted in a vehicle, a controller in a ground fault detector alters the threshold in conformity to a capacitance of a common mode capacitor of which value is different between a first state that a system main relay is ON and a second state that the system main relay is OFF, thereby judges the ground fault on the basis of the altered threshold. Thus the ground fault detector can adequately detect the ground fault in conformity to the capacitance of the common mode capacitor. Thus the detector can detect the ground fault with accuracy without complicated circuitry.

Abstract: A voltage monitoring device monitors voltage of each of battery cells connected in series to one another to configure an assembled battery. The device includes a capacitor circuit, a filter circuit, an input side connection switching unit, a potential difference detection unit, and an output side connection switching unit. The capacitor circuit includes a plurality of capacitors connected in series to one another. The filter circuit includes a plurality of resistors connected to an electrode terminal of each of the battery cells. The plurality of resistors are divided into a first resistor group and a second resistor group. The first resistor group is connected to a connection end between adjacent capacitors of the plurality of capacitors. The second resistor group is connected to an independent end of the plurality of capacitors. A resistance value of the first resistor group is smaller than a resistance value of the second resistor group.

Abstract: A plurality of voltage switching circuits 41 are provided in a switching unit 40 to relatively change a reference voltage to plural levels, thus detecting a spontaneous change of the reference voltage. A range of relative change in the reference voltage by the plurality of voltage switching circuits 41 is set to a usage voltage range 81 or 82 as a part of a total voltage range 80 of each of cells 1a to 1d. This eliminates the need to provide voltage switching circuits 41 required to relatively change the reference voltage over the total voltage range of each of the cells 1a to 1d, making it possible to minimize the number of the voltage switching circuits 41 for each of the cells 1a to 1d. Thus, it is possible to prevent the size of a battery pack control apparatus 2 from increasing.

Abstract: A first monitor circuit 50 and a second monitor circuit 60 each having an identical configuration are provided in a voltage monitor. A threshold switching section 41 switches a threshold of each of switching units 51 and 61 provided in the respective monitor circuits 50 and 60 to a same value. Each of comparators 53 and 63 compares the threshold with a reference voltage to output a result of the comparison. A fault detecting section 42 compares the respective outputs from the comparators 53 and 63 with each other to detect a characteristic shift of the threshold of each of the monitor circuits 50 and 60.

Abstract: A battery voltage monitoring device for efficiently equalizing cell voltages of a plurality of battery cells connected in series through a direct charge transfer between mutually distant battery cells. The device includes a charge-transfer circuit configured to perform a direct charge transfer from a first battery cell to a second battery cell that is fifth or higher adjacent to the first battery cell. This can eliminate charge-transfer losses that would occur during sequential charge transfers between adjacent battery cells, which leads to an efficient charge transfer between mutually distant battery cells.

Abstract: Each monitor IC in the apparatus obtains operation power from a block including cells that are the objects to be monitored. The monitor IC includes a consumption-current adjusting circuit that adjusts a consumption current used from the operation power to a target value. In each monitor IC, the consumption current is adjusted to have the target value by the consumption-current adjusting circuit, and thus the consumption currents of the monitor ICs can be equalized, even if a different number of cells are connected to each monitor IC. Accordingly, it is possible to prevent the variation in the consumption currents among the monitor ICs.

Abstract: There is disclosed a battery monitoring device including a voltage equalization circuit that equalizes cell voltages of a plurality of battery cells being connected in series and forming a battery pack, and a microcomputer that outputs an instruction signal to instruct the voltage equalization circuit to start an voltage equalizing operation for the battery cells. The microcomputer includes a first timer section that stops the voltage equalizing operation a first predetermined set time after the start of the voltage equalizing operation, and the voltage equalization circuit includes a second timer section that stops the voltage equalizing operation a second predetermined set time after the start of the voltage equalizing operation. This can enhance reliability during the voltage equalizing operation.

Abstract: The battery pack monitoring apparatus is for monitoring a battery pack constituted of battery blocks connected in series and each including battery cells connected in series. The battery pack monitoring apparatus includes a cell monitoring circuits provided respectively for the battery blocks, and a control circuit. Each of the cell monitoring circuits includes a cell voltage detection circuit to detect cell voltages of the battery cells included in a corresponding one of the battery blocks, and a block voltage detection circuit to detect a block voltage of the corresponding one of the battery blocks. The control circuit is configured to detect states of the battery cells based on the cell voltages and the block voltages transmitted from the respective cell monitoring circuits.

Abstract: In a flying capacitor type battery voltage detector on a circuit substrate, a large number of photo MOS switches having performance highly depending from temperature are dividedly disposed on front and back surfaces of the circuit substrate such that the photo MOS switches of the back surface are lying over the photo MOS switches of the front surface. Each of pairs of photo MOS switches connects a pair of surface lines with first and second floating lines to transmit an output voltage of each cell of a battery pack connected with the surface lines to a differential amplifier through a flying capacitor connected with the floating lines. Because of the division of the photo MOS switches on the surfaces of the circuit substrate, temperatures of the photo MOS switches have less dispersion, and an S/N ratio of each signal indicating the output voltage can be improved.

Abstract: In a flying capacitor type battery voltage detector on a circuit substrate, a large number of photo MOS switches having performance highly depending from temperature are dividedly disposed on front and back surfaces of the circuit substrate such that the photo MOS switches of the back surface are lying over the photo MOS switches of the front surface. Each of pairs of photo MOS switches connects a pair of surface lines with first and second floating lines to transmit an output voltage of each cell of a battery pack connected with the surface lines to a differential amplifier through a flying capacitor connected with the floating lines. Because of the division of the photo MOS switches on the surfaces of the circuit substrate, temperatures of the photo MOS switches have less dispersion, and an S/N ratio of each signal indicating the output voltage can be improved.

Abstract: A control apparatus for an electric vehicle includes a device for detecting a degree of depression of an accelerator pedal in the electric vehicle, and for outputting an accelerator depression degree signal representing the detected degree of depression of the accelerator pedal. A polyphase ac motor is operative for driving the electric vehicle. A rotational speed of the polyphase ac motor is detected, and a motor rotational speed signal is generated which represents the detected rotational speed of the polyphase ac motor. A battery in the vehicle generates dc power. An inverter changes the dc power into ac power through pulse width modulation responsive to a PWM modulation signal, and outputs the ac power to the polyphase ac motor to drive the latter. A steady torque command value is calculated on the basis of the motor rotational speed signal and the accelerator depression degree signal.