A leakage current detection device connected between a power source and a load, which includes a self-testing or leakage current detection selection trigger unit, for selecting a leakage current detection mode or a self-testing mode; a self-testing unit, for periodically generating a simulated leakage current signal in the self-testing mode; and a leakage current detection unit, for detecting a leakage current signal in the leakage current detection mode and detecting the simulated leakage current signal in the self-testing mode. The selection trigger unit further causes the power source to be disconnected from the load when a leakage current signal is detected, and sends a self-testing result to the self-testing unit depending on whether the leakage current detection unit detects the simulated leakage current signal. The self-testing unit displays an indication of the self-testing result.

The present disclosure relates to an earth leakage circuit breaker and a method for controlling the same. The earth leakage breaker includes a zero-phase current detection unit for detecting a zero-phase current generated in a zero current transformer formed in three-phase electrical lines; a voltage detection unit for detecting a voltage from each of the two electrical lines; a trip unit for tripping contact points between the two electrical lines and a single-phase load when a trip signal is inputted; and a control unit which, when the zero-phase current is detected by the zero-phase current detection unit, detects an electrical line in which the voltage has dropped by a predetermined level or more, and generates and outputs the trip signal to the trip unit when the electrical line in which the voltage has dropped by a predetermined level or more exists.

A protective redundancy circuit is provided for a power tool having an electric motor. The protective redundant subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module that controls the switching operation of the motor switch; and a protective control module that monitors switching operation of the motor switch and disables the power tool when the switching operation of the motor switch fails. In the context of an AC powered tool, the switching operation of the motor switch is correlated to and synchronized to the waveform of the AC input signal. During each cycle or half cycle, the motor control module introduces a delay period before closing the motor switch and the protective control module determines the operational status of the motor switch by measuring the voltage across the motor switch during the delay period.

A selectivity module for dividing a load current in an installation system includes a housing, a plurality of branches in the housing, a plurality of switching devices, and a control unit. Each of the plurality of switching devices is configured for switching a branch current on and off in a corresponding one of the plurality of branches. The plurality of switching devices serves to output information about corresponding switching states. The control unit is connected to the plurality of switching devices and configured to output a status signal as a function of the output information from the plurality of switching devices. The output information relating to the individual switching states of all of the plurality of switching devices is contained in the status signal in a serial encoded form.

A selectivity module for dividing a load current in an installation system includes a housing, a plurality of branches in the housing, a plurality of switching devices, and a control unit. Each of the plurality of switching devices is configured for switching a branch current on and off in a corresponding one of the plurality of branches. The plurality of switching devices serves to output information about corresponding switching states. The control unit is connected to the plurality of switching devices and configured to output a status signal as a function of the output information from the plurality of switching devices. The output information relating to the individual switching states of all of the plurality of switching devices is contained in the status signal in a serial encoded form.

A voltage transformer includes: a body with primary windings and secondary windings coupled to each other by electromagnetic induction; a measuring device electrically connected to the secondary windings via a first fuse; and a relay having a coil and at least one pole with normally open contacts, the at least one pole being configured to be thrown by an energizing of the coil. The coil is arranged in series with the primary windings. The at least one pole with normally open contacts is arranged between the secondary windings via the first fuse in order to short circuit the first fuse when the at least one pole is thrown.

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.

An electronic switch has a first, a second and a third connection and is configured to disconnect a current flow between the first and the second connection. An energy source is connected between the first and the third connection, and a regenerative load is connected between the second and the third connection. The electronic switch includes a semiconductor switch capable of switching currents of different polarity. A fuse is connected between the first connection and the semiconductor switch. A first short-circuiter is connected between the input of the semiconductor switch and the third connection, and a second short-circuiter is connected between the output of the semiconductor switch and the third connection. The fuse has a current trigger threshold between a permanently permitted current and a maximally permitted current of the semiconductor switch. An electrical network having such electronic switch and a method for operating an electronic switch are disclosed.

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.

A solid state switching device, such as a solid state circuit breaker, includes at least one heat sink, a control electronics printed circuit board (PCB), and power electronics. The power electronics are useful to regulate the flow of current from one terminal of the solid state switching device to another terminal. The power electronics can include one or more solid state devices such as FETs, Thyristors, Thyristors+SiC JFET in parallel, IGBTs, and IGCTs. The control PCB can include a variety of circuit elements useful to perform the function of a gate driver useful to activate the solid state device of the power electronics. The heat sink includes one or more signal vias formed therethrough to permit nesting of the control PCB within the heat sink.