Abstract: A distributed base station, including a power system, a power supply apparatus, and at least two radio remote units RRUs, where one end of the power supply apparatus is connected to the power system and the other end is connected to the at least two RRUs; and the power supply apparatus is configured to receive power output by the power system and provide the power for the at least two RRUs, where a distance between any one RRU connected to the power supply apparatus and the power supply apparatus is less than a distance between the RRU and the external power system. In addition, the present invention further provides a communications system.

Abstract: A distributed base station, including a power system, a power supply apparatus, and at least two radio remote units RRUs, where one end of the power supply apparatus is connected to the power system and the other end is connected to the at least two RRUs; and the power supply apparatus is configured to receive power output by the power system and provide the power for the at least two RRUs, where a distance between any one RRU connected to the power supply apparatus and the power supply apparatus is less than a distance between the RRU and the external power system. In addition, the present invention further provides a communications system.

Abstract: A surge protection circuit includes a surge protection unit and an interface electrically connected to each other. The surge protection unit includes an internal connection terminal block, three varistors and one discharge tube. The three varistors are electrically connected to the internal connection terminal block, where two varistors are electrically connected to the discharge tube. The discharge tube is also electrically connected to the internal connection terminal block and is grounded. The surge protection circuit can avoid connecting a varistor to the discharge tube in series and reduce a residual voltage of the surge protection circuit.

Abstract: Embodiments of the present disclosure disclose an electronic heater and a method for controlling the same and relate to the field of power electronic technologies, so as to reduce a maintenance cost of a spare part of the electronic heater. The electronic heater includes: an auxiliary power supply unit, a control unit, a power adjusting unit, and a heating source. The auxiliary power supply unit is configured to supply power to the control unit; the control unit is configured to output a detection voltage signal according to an input voltage of the heating source, output a power control signal according to a preset reference power value, and transmit the detection voltage signal and the power control signal to the power adjusting unit; and the power adjusting unit is configured to obtain an output power adjustment signal according to the detection voltage signal and the power control signal.