Abstract: The present disclosure discloses a codebook feedback method, a terminal device and a network device. The codebook feedback method, comprising: selecting, by a terminal device, M frequency domain Discrete Fourier Transform (DFT) vectors from a DFT array; determining, by the terminal device, a first frequency domain DFT vector indication set from a plurality of frequency domain DFT vector indication sets according to the M frequency domain DFT vectors, wherein an indication of the M frequency domain DFT vectors is equivalent to a first frequency domain DFT vector indication in the first frequency domain DFT vector indication set, and M is a positive integer; and sending, by the terminal device, an indication message to the network device, wherein the indication message is used for indicating the first frequency domain DFT vector indication set.

Abstract: This application discloses a compensation circuit and method for potential induced degradation, a power module, and a photovoltaic system. The compensation circuit includes a switch, a first resistor, and a controller. The switch and the first resistor are connected in series, a first end of the compensation circuit is connected to a positive output end PV+ of a photovoltaic module, and a second end of the compensation circuit is connected to a second end of a first DC-DC converter. The controller is configured to control the switch to be closed when output voltage of the photovoltaic module is less than preset voltage, so that the first DC-DC converter provides electric energy of the battery to the second end of the compensation circuit. A second resistor is connected between the positive output end PV+ and a negative output end PV? of the photovoltaic module.

Abstract: A golden finger and a board edge interconnecting device are disclosed. The golden finger includes a printed circuit board (PCB) surface layer and at least one PCB inner layer, where a metal foil of the PCB inner layer is connected to a metal foil of the PCB surface layer through a current-carrying structure, so that a current-carrying channel of the golden finger passes through the PCB surface layer and the PCB inner layer. The board edge interconnecting device includes the foregoing golden finger. In the embodiments, a current-carrying capacity of a PCB in the golden finger is increased without increasing a size and thickness of a copper foil of the PCB in the golden finger, thereby effectively improving the current-carrying capacity of the PCB in the golden finger.

Abstract: A golden finger and a board edge interconnecting device are disclosed. The golden finger includes a printed circuit board (PCB) surface layer and at least one PCB inner layer, where a metal foil of the PCB inner layer is connected to a metal foil of the PCB surface layer through a current-carrying structure, so that a current-carrying channel of the golden finger passes through the PCB surface layer and the PCB inner layer. The board edge interconnecting device includes the foregoing golden finger. In the embodiments, a current-carrying capacity of a PCB in the golden finger is increased without increasing a size and thickness of a copper foil of the PCB in the golden finger, thereby effectively improving the current-carrying capacity of the PCB in the golden finger.