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.

An electrical wiring device including a housing assembly including a plurality of terminals at least partially disposed therein, the plurality of terminals including a HOT/LOAD terminal, a NEUTRAL terminal, a first traveler terminal, and a second traveler terminal, wherein, when in use, at least one of the terminals is connected to line hot; a first series FET and a second series FET disposed in series between the HOT/LOAD terminal and one of the first traveler terminal or the second traveler terminal; at least one of a first sensor producing a first sensor output according to current flow or a voltage at the one of the first traveler terminal or the second traveler terminal and a second sensor producing a second sensor output according to current flow through the NEUTRAL terminal or according to a voltage between the first series FET and second series FET; and a controller configured to determine to which of the plurality of terminals line hot is connected based, at least, on the first sensor output or the second sensor output and to provide, during operation, at least one of a first control signal to the first series FET and a second control signal to the second series FET according to a user adjustable load setting.

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.

An electric oil pump includes a control substrate including a reverse connection protection circuit to protect a circuit in the substrate, a first substrate wiring connected to a source terminal of a MOSFET in the reverse connection protection circuit, a second substrate wiring connected to a GND terminal, and a bypass circuit that causes a current to flow from the first substrate wiring to the second substrate wiring in a case in which an output voltage of the external power supply is equal to or greater than a predetermined value that is greater than a rated voltage, in which the predetermined value is a value that is smaller than a withstanding voltage between a gate and the source of the MOSFET.

A battery protection circuit has two input nodes and two output nodes. The input nodes are connected to a positive supply line and a negative or ground line respectively, and the two output nodes are connected to a positive side of a load and a negative or ground return side of the load. The circuit includes a solid state switch which is oriented such that when the switch is open current cannot flow from the battery through the load. At least one capacitor is connected in series with a diode between the two input nodes of the circuit to smooth out any negative transient voltages present at the positive input node of the circuit. The capacitor includes a polarized capacitor and the diode is oriented to protect the capacitor during normal use when a positive voltage is present at the input node that is connected to the positive supply line.

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 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.

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.

A polarity reversal protection arrangement having a transistor circuit, an amplifier circuit and an output driver stage, wherein the amplifier circuit is connected to the output driver stage and the output driver stage is connected to the transistor circuit and the transistor circuit is arranged between a first connection node and a second connection node of the polarity reversal protection arrangement, such that an electrical connection between the first connection node and the second connection node is able to be created or disconnected by way of the transistor circuit, wherein the output driver stage is designed as a tri-state stage. A method for operating the polarity reversal protection arrangement and to a corresponding use.

A protection circuit is provided. A control circuit receives an input voltage. In a case that the input voltage is lower than a negative threshold voltage, the control circuit outputs a first control voltage to a surge bleeder circuit through a first output end of the control circuit, to control the surge bleeder circuit to discharge the input voltage and output a first bleeder current. In a case that the input voltage is higher than a positive threshold voltage, the control circuit outputs a second control voltage to the surge bleeder circuit through a second output end of the control circuit, to control the surge bleeder circuit to discharge the input voltage and output a second bleeder current.