A protection device configured for being electrically connected to a test tap of a HV bushing for protecting the bushing from transient overvoltages. The protection device includes at least two parallel connected protection branches connected between the test tap and a ground connector configured for connecting to ground. Each of the protection branches includes a plurality of parallel connected gas discharge tubes, a Transient-Voltage-Suppression (TVS) diode connected in series with the gas discharge tubes, and a resistor connected in series with the gas discharge tubes and across the TVS diode.

A power supply device may include a connector configured to electrically couple the power supply device to a conductor of the underground power lines; a voltage divider configured to receive an input voltage from the conductor, the voltage divider comprising a capacitor and divider voltage control electronics in series with the capacitor; and, a surge resistor in series with the capacitor and configured to provide impulse protection from surge events. The divider voltage control electronics may be configured to regulate an output voltage of the voltage divider to support variable loads on the voltage divider.

An electronic apparatus is provided. The electronic apparatus includes: a main circuit; and a power supply circuit configured to receive external power from an external power supply and supply operating power to the main circuit. The power supply circuit includes: a converter; and a lightning protection circuit that includes: a varistor configured to have a first rated voltage corresponding to a breakdown voltage of a device of the converter; and a surge arrester connected in series to the varistor and configured to have a second rated voltage, and based on the external power being higher than the first rated voltage of the varistor, the varistor is clamped so that a voltage applied to the converter does not exceed the first rated voltage, and based on a voltage applied to the surge arrester being equal to or higher than the second rated voltage, the surge arrester is short-circuited.

Disclosed are a surge protection device and a chip constituted thereby, and a communication terminal. The surge protection device comprises an input pad and an output pad. The input pad is connected to a power supply voltage, and the output pad is connected to a ground wire. NMOS transistor groups are provided between the input pad and the output pad. The NMOS transistor groups are connected to the input pad and the output pad respectively by means of metal wires. The structures of the metal wires between the NMOS transistor groups and the input pad and the output pad respectively and/or the structures of the NMOS transistor groups are changed to reduce or cancel non-uniform turn-on of the NMOS transistor groups caused by metal wires having different lengths from the NMOS transistor groups to the input pad and the output pad respectively along a power supply voltage wire direction.

An electromagnetic interference (EMI) filter 32 is provided which is suitable for a DC motor 10. The EMI filter 32 comprises an EMI suppression circuit 34 having first and second DC-motor-terminal inputs 36a, 36b, and an MW-band power choke 44 coupled to one of the first and second DC-motor-terminal inputs 36a, 36b to increase the motor inductance in the MW frequency band.

Methods of powering a radio that is mounted on a tower of a cellular base station are provided in which a direct current (“DC”) power signal is provided to the radio over a power cable and a voltage level of the output of the power supply is adjusted so as to provide a substantially constant voltage at a first end of the power cable that is remote from the power supply. Related cellular base stations and programmable power supplies are also provided.

A three-output DC voltage supply for providing a positive, an intermediate, and a negative voltage supply is provided which includes a positive DC voltage bus and a negative DC voltage bus configured to be connected to a DC power source, a first voltage divider connected between the positive DC voltage bus and the negative DC voltage bus, wherein the first voltage divider includes a voltage-setting component and a resistive component, and a short-circuit protection component including first and second transistors of opposite types connected between the voltage-setting component and the resistive component, wherein a base of the first transistor is connected to a collector of the second transistor to define a first base/collector node, a base of the second transistor is connected to a collector of the first transistor to define a second base/collector node, and the intermediate voltage supply is provided by either the first or second gate/collector nodes.

A power supply circuit includes a transistor having a drain connected to an input voltage, a gate, and a source; a diode; a choke coil; a capacitor; a transformer; a control circuit that provides a drive signal for turning on and off the transistor to a primary winding of the transformer based on an output voltage; an overvoltage detection circuit that outputs an overvoltage signal when the output voltage is an overvoltage; and a short circuit that short-circuits the gate and the source of the transistor in response to the overvoltage signal.

An arrangement contains a polyphase transformer which has primary windings and secondary windings. The secondary windings are connected to form a star circuit, the star point of which is connected to earth potential by means of an overvoltage-limiting device. The overvoltage-limiting device has a first overvoltage-limiting component. A switch, which electrically bridges the first overvoltage-limiting component in its closed state, is assigned to the first overvoltage-limiting component.

A short-circuit semiconductor component comprises a semiconductor body, in which a rear-side base region of a first conduction type, an inner region of a second complementary conduction type, and a front-side base region of the first conduction type are disposed. The rear-side base region is electrically connected to a rear-side electrode, and the front-side base region is electrically connected to a front-side electrode. A turn-on structure, which is an emitter structure of the second conduction type, is embedded into the front-side base region and/or rear-side base region and is covered by the respective electrode and is electrically contacted with the electrode placed on the base region respectively embedding it. It can be turned on by a trigger structure which can be activated by an electrical turn-on signal. In the activated state, the trigger structure injects an electrical current surge into the semiconductor body, which irreversibly destroys a semiconductor junction.