In a reverse connection protection circuit, a protection element enters a conductive state when the power source is electrically connected in a forward direction to a load-side circuit and enters a non-conductive state when the power source is electrically connected in a reverse direction to the load-side circuit. The protection element has a first terminal electrically connected to a power source-side terminal of, and a second terminal electrically connected to a load-side terminal of the switching element. A booster circuit is electrically connected to the load-side terminal to supply a boosted voltage of more than a power source voltage to the load-side terminal. A voltage detection part is connected to the load-side terminal to detect an output voltage of the switching element. A judgment part is connected to the voltage detection part to detect a switching element failure based of the voltage detected by the voltage detection part.

A battery reverse polarity protection circuit is disclosed. The battery reverse polarity protection circuit includes a field effect transistor (FET) coupled to a control circuit. The FET is configured to transmit an input voltage from a normal-polarity-connected battery to an output terminal, and block the input voltage from a reverses polarity-connected battery to the output terminal. The control circuit is coupled to the input terminal, the output terminal, and a common terminal and is configured to detect, during transmission of the input voltage from the normal-polarity-connected battery to the output terminal, that the input voltage is less than an output voltage, indicating onset of an abnormal operating mode, and turn off the FET to prevent the output voltage from being affected by the input voltage during the abnormal operating mode.

A battery reverse polarity protection circuit is disclosed. The battery reverse polarity protection circuit includes a field effect transistor (FET) coupled to a control circuit. The FET is configured to transmit an input voltage from a normal-polarity-connected battery to an output terminal, and block the input voltage from a reverses polarity-connected battery to the output terminal. The control circuit is coupled to the input terminal, the output terminal, and a common terminal and is configured to detect, during transmission of the input voltage from the normal-polarity-connected battery to the output terminal, that the input voltage is less than an output voltage, indicating onset of an abnormal operating mode, and turn off the FET to prevent the output voltage from being affected by the input voltage during the abnormal operating mode.

A reverse polarity protection device includes a protection unit, a detection unit, and a control unit electrically connected between a power supply device and a load device. The detection unit is electrically connected to the power supply device for detecting the polarity of an output signal of the power supply device, and the control unit is electrically connected to the detection unit and the protection unit. The detection unit outputs a detection signal to the control unit according to a detection result of the polarity of the output signal. If the detection signal shows that the polarity of the output signal is reverse, the control unit will control the protection unit to form an open circuit between the power supply device and load device to stop transmitting the output signal of the power supply device to the load device and achieve a reverse polarity protection effect of the load device.

A reverse polarity protection device includes a protection unit, a detection unit, and a control unit electrically connected between a power supply device and a load device. The detection unit is electrically connected to the power supply device for detecting the polarity of an output signal of the power supply device, and the control unit is electrically connected to the detection unit and the protection unit. The detection unit outputs a detection signal to the control unit according to a detection result of the polarity of the output signal. If the detection signal shows that the polarity of the output signal is reverse, the control unit will control the protection unit to form an open circuit between the power supply device and load device to stop transmitting the output signal of the power supply device to the load device and achieve a reverse polarity protection effect of the load device.

A reverse current protection circuit for a switch circuit includes a reverse current control circuit and an enable/disable circuit coupled to the reverse current control circuit. The reverse current control circuit is coupled to an input terminal and an output terminal of the switch circuit, and disconnects the output terminal of the switch circuit from the input terminal of the switch circuit when an output voltage of the switch circuit is higher than a first predetermined voltage. The enable/disable circuit disables the reverse current control circuit for a first predetermined time period when the output voltage of the switch circuit becomes lower than the first predetermined voltage after being higher than the first predetermined voltage, and enables the reverse current control circuit after the first predetermined time period.

A reverse current protection circuit for a switch circuit includes a reverse current control circuit and an enable/disable circuit coupled to the reverse current control circuit. The reverse current control circuit is coupled to an input terminal and an output terminal of the switch circuit, and disconnects the output terminal of the switch circuit from the input terminal of the switch circuit when an output voltage of the switch circuit is higher than a first predetermined voltage. The enable/disable circuit disables the reverse current control circuit for a first predetermined time period when the output voltage of the switch circuit becomes lower than the first predetermined voltage after being higher than the first predetermined voltage, and enables the reverse current control circuit after the first predetermined time period.

A method of regulating the operation of an electrical system, the electrical system including, a contactor unit including a contactor and a conductive element, sensing circuitry including at least two Hall Effect sensors, and a control unit including at least a trip circuit, an I2t unit, and a one coil current monitor. The method includes receiving, by the control unit, one or more first measurements, from the sensing circuitry and determining, by the control unit, a current corresponding to a current in the at least one conductive element based on the one or more first measurements. The control unit also determines an instantaneous power generated by a load based on the current and regulates the operation of the contactor unit based on the power generated by the load.

A method of regulating the operation of an electrical system, the electrical system including, a contactor unit including a contactor and a conductive element, sensing circuitry including at least two Hall Effect sensors, and a control unit including at least a trip circuit, an I2t unit, and a one coil current monitor. The method includes receiving, by the control unit, one or more first measurements, from the sensing circuitry and determining, by the control unit, a current corresponding to a current in the at least one conductive element based on the one or more first measurements. The control unit also determines an instantaneous power generated by a load based on the current and regulates the operation of the contactor unit based on the power generated by the load.

The ECU includes first and second power terminals, first and second voltage limiting elements, first and second diodes, and a power supply IC. A voltage is applied to the first power terminal from a battery, and a voltage is applied to the second power terminal from the battery via a start switch. The first voltage limiting element is provided between the first power terminal and an input terminal of the power supply IC. The cathode of the first diode is connected to the input terminal of the power supply IC. The second voltage limiting element is provided between the second power terminal and the anode of the first diode. The cathode of the second diode is connected to the anode of the first diode, and the anode is grounded. A limit voltage of the first voltage limiting element is greater than a limit voltage of the second voltage limiting element.