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.

An input node is configured to receive a supply signal which may be of a first polarity or a second polarity opposite the first polarity. A high input current circuit couples the input node to an output node through at least one power transistor having a control electrode. A low input current circuit couples a supply current from the input node to control circuit configured to control the power transistor. A circuit is provided to detect polarity reversal with respect to the supply signal. A protection circuit for the low input current circuit operates to decouple the control circuit from the input node if the supply signal has the second polarity. A protection circuit for the high input current circuit operates to short-circuit the control electrode of the power transistor to the current path provided by the power transistor between the input node and the output node.

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 power feeding control device, N-channel first FET and second FET are located in a current path for current flowing from a positive terminal to a negative terminal. The drain of the first FET is located downstream of the source. The drain of the second FET is located upstream of the source. The cathode of a first diode is connected to the negative terminal. A first drive circuit and a second drive circuit switch ON or OFF the first FET and the second FET by adjusting the gates of the first FET and the second FET, with respect to the cathode of the first diode.

A direct-current power supply parallel-machine input reverse connection prevention circuit and a server. The circuit comprises a first switch tube, second switch tube (Q2). A first end of the first switch tube is used for being connected to a positive end of a first power supply and a second end of the first switch tube is connected to a positive input end of a first driving module. A first end of the second switch tube is used for being connected to a positive end of a second power supply and a second end of the second switch tube is connected to a positive input end of a second driving module.

According to an embodiment, a surge protector includes a capacitor, a switch, and a first transistor. The capacitor charges based on an input power to the surge protector. The switch turns on when the capacitor is charged to a charge threshold. The surge protector outputs the input power when the switch is turned on. The first transistor turns on when a voltage of the input power exceeds a first input voltage threshold such that the capacitor discharges to below the charge threshold and such that the switch turns off. The surge protector stops outputting the input power when the switch is turned off.

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.

This application discloses a protection circuit for preventing a misconnection at an input end and a photovoltaic power generation system, and relates to the field of power electronics technologies. The protection circuit includes an input end, a misconnection detection unit, a mechanical interlocking unit, and a switch unit. The input end is configured to connect to an output end of a direct current power supply. A first input end of the misconnection detection unit is connected to a first port of the input end, and a second input end of the misconnection detection unit is connected to a second port of the input end. An output end of the misconnection detection unit is coupled to the mechanical interlocking unit. The mechanical interlocking unit is connected to the switch unit. A first end of the switch unit is configured to connect to the input end, and a second end of the switch unit is configured to connect to a next circuit. The misconnection detection unit is configured to: when connection wires of the first port and the second port are incorrect, control the mechanical interlocking unit to keep the first end of the switch unit and the second end of the switch unit in a disconnected state. When positive and negative poles of a power supply connected to the input end are misconnected, the protection circuit can be used to prevent a circuit from being affected by the misconnection.