An overvoltage protection circuit includes an input terminal, an output terminal, a clamp transistor, and a selector circuit. The clamp transistor is configured to control current flow between the input terminal and the output terminal. The clamp transistor includes a first terminal coupled to the input terminal, a second terminal coupled to the output terminal. The selector circuit is configured to control a resistance of the clamp transistor based on a voltage at the input terminal. The selector circuit includes a first terminal coupled to the first terminal of the clamp transistor, a second terminal coupled to the second terminal of the clamp transistor, and a third terminal coupled to a third terminal of the clamp transistor.

A blower filter device (3) is connectable to a voltage supply unit (2) and includes a blower unit (5), a filter mount (14), an internal energy storage unit (7), an energy interface (9), a current limitation device (13), a sensor array (16, 17, 18) and a control device (6). The current limitation device is activated upon disconnecting the energy interface from the voltage supply unit. The activated current limitation device limits the intensity of a current from the energy interface to the internal energy storage device. Upon the voltage supply unit being connected to the energy storage device and a predefined deactivating event is detected, the control device deactivates the current limitation device. The deactivating event is based on a charging voltage of the internal energy storage unit and/or on a time period that has elapsed since the connection. A process is provided for operating such a blower filter device.

The present disclosure relates to electrostatic protection terminals. One example terminal includes a target interface, a protected circuit, a protection unit, a switch unit, and a switch control unit. The protected circuit is configured to suppress an electrostatic discharge (ESD) current or an electrical overstress (EOS) current. A first end of the protection unit is electrically connected to a first pin of the target interface. A second end of the protection unit is electrically connected to a second pin of the protected circuit. The first pin is any pin of the target interface. The second pin is a pin that is in the protected circuit and that needs to be electrically connected to the first pin. The switch unit is connected to the protection unit in parallel. The switch control unit is configured to control the switch unit to be open or closed.

A hot swap controller circuit includes a comparator and current control circuitry. The comparator is configured to compare voltage across a power transistor controlled by the hot swap controller circuit to a predetermined threshold voltage. The current control circuitry is coupled to the comparator. The current control circuitry is configured to limit current through the power transistor to no higher than a predetermined high current based on the voltage across the transistor being less than the predetermined threshold voltage. The current control circuitry is also configured to limit the current through the transistor to be no higher than a predetermined low current based on the voltage across the transistor being greater than the predetermined threshold voltage. The predetermined high current is greater than the predetermined low current.

A circuit includes input terminals adapted to be coupled to a battery; a ground terminal; and an electrostatic discharge (ESD) protection circuit coupled to the input terminals. The ESD protection circuit includes: a switch coupled between the ground terminal and the input terminals; and a control circuit coupled to the input terminals and to the switch. The control circuit is configured to: detect an ESD event at one of the input terminals; detect a transient voltage at one of the input terminals, in which the transient voltage is caused by an initial coupling of that input terminal to the battery; detect a condition in which the switch has been closed for longer than a threshold amount of time; close the switch responsive to the detected ESD event; and open the switch responsive to the detected transient voltage or the detected condition.

A hot-swap circuit for providing soft start and overcurrent protection to an electronic circuit may include a controller and a timer. The controller may be configured to sense an electrical current associated with the hot-swap circuit, based on the electrical current sensed, perform current limiting of the electrical current to minimize inrush current to the electronic circuit, and disable the electrical current from flowing to the electronic circuit in response to the electrical current exceeding an overcurrent threshold for longer than a duration of a fault timer. The timer circuit may be configured to, for a period of time after enabling of the hot-swap circuit, cause the duration of the fault timer to be a first duration, and after the period of time, cause the duration of the fault timer to be a second duration significantly shorter than the first duration.

A system and method for compensating for voltage drops in a device having a remote node is disclosed. A power supply unit has an adjustable voltage output and a feedback circuit. A power path is coupled to the power supply unit to supply voltage to the remote node. A switch has an output coupled to the feedback circuit, a first input coupled to the power path, and a second input coupled to the remote node. A controller is coupled to the switch. The controller is operable to control the switch to switch between the inputs to cause the feedback circuit of the power supply unit to compensate the voltage output for a voltage drop on the power path or the remote node.

A technique is provided for detecting decoupling of a first connector part, connected to a first device, of an electrical plug connector from a second connector part, connected to a second device, of the electrical plug connector. A corresponding method, a corresponding apparatus, a corresponding electrical plug connector as well as the first connector part and the second connector part of the plug connector, a corresponding device and a computer program product are stated.

An electric power tool includes: a motor; a driving circuit configured to drive the motor to output motive power; a control module configured to control the driving circuit; an energy storage element connected to the driving circuit; a current limiting element connected in series with the energy storage element and configured to charge the energy storage element with a first current; a switching element electrically connected in series with the energy storage element, connected in parallel with the current limiting element, and configured to charge or discharge the energy storage element with a second current. The electric power tool can avoid the occurrence of adverse situations such as generating electric sparks at the connection terminals of the electric power tool and of a battery pack when the battery pack is inserted into the electric power tool.

An electronic fuse (e-fuse) for controlling input current of a load includes a transistor switch and a transorb device that is coupled in parallel to the transistor switch between a source and a drain of the transistor switch. A circuit comprising the transistor switch and the transorb device in parallel comprises a first end and a second end. The first end of the circuit is coupled to a power bus. The second end of the circuit is coupled to a first node of the load. The e-fuse includes an RC circuit comprising a resistor coupled in series with a first capacitor. The RC circuit is coupled between the power bus at the first end of the circuit and a return. The return is coupled to a second node of the load. The e-fuse includes a second capacitor that is coupled between the return and the second end of the circuit.