HDMI signal sending device and receiving device and power supply system based on HDMI interface

The invention discloses an HDMI signal sending device and receiving device and a power supply system based on an HDMI interface and comprising the HDMI signal sending device and receiving device. In the HDMI signal sending device, a fourteenth pin is grounded, the HDMI signal sending device provided by the invention comprises an MOS tube, the connection of the MOS tube is controlled by the voltage on the fourteenth pin, after the HDMI signal sending device provided by the invention and the HDMI signal receiving device provided by the invention are connected together by the HDMI, the fourteenth pin of a second HDMI interface of the HDMI signal receiving device is also grounded, at this time, the grid voltage of a PMOS tube is 0, the grid voltage of an NMOS tube is a high level, the MOS tube is connected, in this way, a working voltage provided by a power supply device of the HDMI signal receiving device can be transmitted to the eighteenth pin of the second HDMI interface, and then the HDMI signal sending devi