A surge arrester, in particular for arresting surges, includes a housing and a disconnecting device. The housing is divided into at least two housing parts, and the disconnecting device connects the housing parts to one another.

A current limiter for selectively limiting a rate of change of current in a DC electrical network may include a first electrical block including an inductive element and a second electrical block including a bidirectional switch. The first electrical block is connected in parallel with the second electrical block between first and second terminals, and the first and second terminals are connectable to the DC electrical network. The bidirectional switch is switchable to: (1) a first mode to permit current flow through the second electrical block in a first current direction and at the same time inhibit current flow through the second electrical block in a second, opposite current direction; and (2) a second mode to permit current flow through the second electrical block in the second current direction and at the same time inhibit current flow through the second electrical block in the first current direction.

A three phase surge protection device is disclosed. In an embodiment a device include a stack comprising a first varistor, a second varistor and a third varistor, wherein the varistors are electrically connected to form a circuit and a first thermal disconnect configured to interrupt the circuit when a temperature of the first thermal disconnect exceeds a predefined temperature.

A thermostat may include first and second solid-state switching elements coupled to a call relay wire connector and a power return wire connector. The switching elements may be configured to operate in a first state to make a connection between the call relay wire connector and the power return wire connector, and a second state in which the connection is interrupted. The thermostat may also include power monitoring circuitry configured to cause the switching elements to operate in the first state to actuate an environmental control function, receive an indication that the switching elements should transition to the second state, at a first time after receiving the indication, turn off whichever of the first switching element and the second switching element receives AC current from the environmental control system at the first time; and at a second time after the first time, turn off the other of the switching elements.

A power conditioning circuit includes at least one power storage device having electrodes coupled for receiving power from a DC power source. At least one active current limit (ACL) circuit coupled to the electrodes of the power storage device is for limiting a maximum power output from the power storage device under fault conditions. A DC-to-DC converter has its inputs coupled to the ACL circuit. At least one crowbar circuit has a first terminal and a second terminal and a shorting device coupled to an output of the DC-to-DC converter for providing output terminals for the power conditioning circuit.

A power switch module comprising a control component. Upon an indicated operating condition fulfilling a protection condition, the control component is arranged to transition the power switch module from an ON state to a latched-OFF state in which the control component is arranged to configure the switching device to be turned off to decouple the load node from the power supply node. Having transition to the latched-Off state, the control component is further arranged to determine whether a voltage level at the load node exceeds a threshold voltage level, and if it is determined that the voltage level at the load node exceeds the threshold voltage level, transition the power switch module from the latched-OFF state to a current-limited state in which the control component is arranged to control the switching device to limit current-flow there through.

The invention relates to a circuit arrangement for combined protection of a load from temporary and transient overvoltages with emergency operation of the load in the presence of a temporary overvoltage and with integrated follow current limitation, wherein a first surge arrester, in particular a spark gap or a varistor, is provided between network-side input terminals and a second surge arrester, in particular a varistor, is provided between load-side output terminals for follow current limitation. According to the invention, at least one controlled semiconductor switch is provided in each case in the series branch between the input terminal and the output terminal and in the output-side parallel branch, wherein a mechanical switch and a series capacitance are connected in parallel with the semiconductor switch in the series branch. Furthermore, the semiconductor switch in the parallel branch is part of a series circuit comprising a parallel circuit comprising a second surge arrester and a parallel capacitance. A series inductance is provided in the series branch between the input terminal and the parallel circuit comprising the series capacitance, the controlled semiconductor switch and the mechanical switch. A microcontroller for controlling the semiconductor switches is also present, wherein the microcontroller is connected to a current detector in the series branch.

The circuit of the present invention comprises a detection module and a feedback module, wherein an output end of a power supply management module is coupled to one end of a voltage level shift module, and the other end of the voltage level shift module is coupled to a first end of the detection module, and a second end of the detection module is coupled to a WOA route module or a GOA route module, and a third end of the detection is coupled to one end of the feedback module, and the other end of the feedback module is coupled to an enable end of the power supply management module, and the detection module detects whether the WOA route module or the GOA route module is short, and feeds back a short signal; the feedback module receives the short signal, and sends a disable signal to the enable end.

Various embodiments include a device for coupling two DC grids comprising source-side and load-side capacitances comprising: a switching device for current regulation, the switching device including two series-connected switching modules;

wherein each of the switching modules includes at least one controllable semiconductor switching element connected in parallel to a respective series circuit comprising a resistor and a capacitor; and a control unit. The control unit is programmed to: switch the controllable semiconductor switching element of one of the two switching modules on and at the same time switch the controllable semiconductor switching element of the other of the two switching modules off; switch the controllable semiconductor switching element of the other of the two switching modules on and at the same time switch the controllable semiconductor switching element of the one of the two switching modules off; repeat steps a) and b) until the voltages of the source-side and load-side capacitances have aligned with one another; and switch the controllable semiconductor switching elements of the two switching modules on.

Circuits for providing overcurrent protection are disclosed herein. The circuits feature depletion mode MOSFETs connected to resistive elements, preferably, Positive Temperature Coefficient (PTC) devices, configured in such a way so that the voltage across the PTC device is the same as the gate-to-source voltage of the MOSFET. The circuit may further be configured using a TVS diode, for clamping the drain-to-source voltage of the MOSFET during the overcurrent events. Heat transfer between the MOSFET and the PTC device facilitates overcurrent protection. A two-terminal device including a depletion mode MOSFET, a PTC device, and a TVS diode may provide overcurrent protection to other circuits. A bidirectional circuit c including two MOSFETS disposed on either side of a PTC is also contemplated for AC voltage overcurrent protection.