An apparatus is described. The apparatus includes a stacked switch circuit having protection circuitry to prevent shoot through current when the switch is in an off state and respective voltages at the terminals of the switch change such that before the change one of the terminals of the switch has the higher voltage and after the change the other terminal of the switch has the higher voltage.

A power system comprises a power source, a transmission line coupled to the power source through a circuit breaker, a shunt reactor coupled to the transmission line, and a current transformer connected in series with the shunt reactor. A method for controlling the circuit breaker of the power system comprises processing an output signal of the current transformer to obtain the voltage on the transmission line by determining a time derivative of a current sensed by the current transformer. The method further comprises performing, by at least one control or protection device, a control or protection operation (e.g., auto-reclosing) based on the determined time derivative of the current sensed by the current transformer.

The invention relates to a restart protection device (1) for a battery-powered electric hand tool (2), comprising—a control capacitor (C.sub.CTRL) having a cathode and an anode, wherein the cathode can be connected to an earth connection (10) of the electric hand tool (2) and the anode can be connected via a battery pack interface (4) of the electric hand tool (2) to a connector wire (6) of a battery pack (3) of the electric hand tool (2); —a controllable discharge circuit (14) designed for discharging the control capacitor (C.sub.CTRL), wherein a control input of the discharge circuit (14) can be connected via the battery pack interface (4) to a signal line (9) of the battery pack (3); —a measuring device (15) designed to determine a charge state of the control capacitor (C.sub.CTRL); and—a control device (13) connected to the measuring device (15), which control device is configured to inhibit start-up of the electric hand tool (2) if the charge state of the control capacitor (C.sub.CTRL) determined by means of the measuring device (15) is below a specified threshold value and an operating switch (12) on the electric hand tool (2) is pressed at the same time.

A power system comprises a power source, a transmission line coupled to the power source through a circuit breaker, a shunt reactor coupled to the transmission line, and a current transformer connected in series with the shunt reactor. A method for controlling the circuit breaker of the power system comprises processing an output signal of the current transformer to obtain the voltage on the transmission line by determining a time derivative of a current sensed by the current transformer. The method further comprises performing, by at least one control or protection device, a control or protection operation (e.g., auto-reclosing) based on the determined time derivative of the current sensed by the current transformer.

A power supply device (100) and a display device (200). The power supply device (100) comprises a drive unit (10), a power source unit (20) and a protection unit (30); the drive unit is configured to drive the display device (200); the power source unit (20) is electrically connected to the drive unit (10); the power source unit (20) is configured to provide electric energy; the protection unit (30) is electrically connected between the drive unit (10) and the power source unit (20); and the protection unit (30) is configured to prevent current recharge.

An arc suppression pre-charge circuit includes a source for providing energy to a load and a main contactor selectively closed to provide energy from the source to the load, wherein the main contactor provides an alternate current path from the source to the load and bypasses a pre-charge branch of the circuit when the main contactor is closed. The pre-charge branch includes a voltage-controlled resistor and a control circuit configured to control a resistance of the voltage-controlled resistor.

Home appliances have operation switches and buttons and also sensors which can be activated by the user. It is possible that the user will cause and an undesired operation to take place by pressing a switch or activating a sensor by a certain action. This can be small children of dementing old people left alone, or any person in the household which can do things by mistake. This invention will describe an apparatus serving as an appliance accessory which can force the voltage value at the appropriate timing and time frame to be put on the appropriate control lines coming in the appliance control board thus maintaining a proper appliance operation.

A power supply device (100) and a display device (200). The power supply device (100) comprises a drive unit (10), a power source unit (20) and a protection unit (30); the drive unit is configured to drive the display device (200); the power source unit (20) is electrically connected to the drive unit (10); the power source unit (20) is configured to provide electric energy; the protection unit (30) is electrically connected between the drive unit (10) and the power source unit (20); and the protection unit (30) is configured to prevent current recharge.

A vehicle power system includes an inverter, outlets, and circuit breakers. The inverter supplies power to the outlets through the circuit breakers. The inverter, in response to detecting no voltage at designated amount and combination of the outlets, based on the designated amount and combination, generates a signal indicating that one or more of electrical paths to the outlets has failed or one or more of the circuit breakers is open.

An apparatus is described. The apparatus includes a stacked switch circuit having protection circuitry to prevent shoot through current when the switch is in an off state and respective voltages at the terminals of the switch change such that before the change one of the terminals of the switch has the higher voltage and after the change the other terminal of the switch has the higher voltage.