Abstract: Disclosed are a three-in-one multimedia cable and an electronic drawing board system. The three-in-one multimedia cable includes a USB-type-C plug, an HDMI plug, a USB-type-A plug, and a power supply plug, the USB-type-C plug is connected to the HDMI plug, the USB-type-A plug, and the power supply plug respectively. The electronic drawing board system includes the three-in-one multimedia cable, a USB-type-C socket, an analog switch, and an electromagnetic screen module, the USB-type-C plug of the multimedia cable is connected to the USB-type-C socket, an output end of the USB-type-C socket is connected to an input end of the analog switch, and an output end of the analog switch is connected to an input end of the electromagnetic screen module. The three-in-one multimedia cable can reduce the number of cables, which is convenient for users to use, and can be widely applied to the field of data cables.

Abstract: Disclosed is an electromagnetic fountain pen, which includes a pen core, a housing, and a pen body located in the housing, the housing includes a front housing and a rear housing, the pen body includes a first iron core and an iron core holder, the iron core holder is provided with a pen core clamp link, a second iron core, and a third iron core, coils are wound outside the first iron core and the second iron core, the first iron core is close to a pen tip of the pen core, the pen core is configured to pass through a center of the first iron core, and then is clamped by one end of the pen core clamp link.

Abstract: Disclosed is a passive electromagnetic fountain pen, which includes a pen core and a pen body, wherein the pen body includes a first iron core and an iron core holder, a pen core clamp link, a second iron core, a third iron core, an elastic component, a pressure regulating plate, and a first structure matched with the pressure regulating plate are disposed sequentially from front to back in the iron core holder, coils are wound outside the first iron core and the second iron core, the first iron core is close to a pen tip of the pen core, the second iron core is fixedly connected with the iron core holder, the pen core is configured to pass through a center of the first iron core, and then be clamped by one end of the pen core clamp link.

Abstract: Disclosed is a passive electromagnetic pen, which includes a pen core, a first iron core, and an iron core holder, wherein a coil is wound outside the first iron core, the first iron core is fixed to an end of the iron core holder close to a pen tip of the pen core, a second iron core, an elastic component, a pressure regulating plate, and a first structure matched with the pressure regulating plate are disposed in the iron core holder sequentially from front to back, and the pen core is configured to pass through a center of the first iron core, and then drive the second iron core to move; and the pressure regulating plate when in rotation is configured to be in surface contact with the first structure by a surface, so as to generate an axial displacement to change an axial displacement of the elastic opponent.

Abstract: Disclosed is an electromagnetic pen, including a housing and a pen body located in the housing, the housing includes a front housing and a rear housing, the pen body includes a pen core, a first iron core, an iron core holder, and a PCBA circuit board, a coil is wound outside the first iron core, the first iron core is fixed at an end of the iron core holder close to a pen tip of the pen core, a second iron core is disposed in the iron core holder, and the pen core is configured to pass through a center of the first iron core, and then drive the second iron core to move; and an elastic structure is disposed between the PCBA circuit board and the iron core holder, a clamping slot is disposed on the PCBA circuit board.

Abstract: Disclosed is an electromagnetic fountain pen, which includes a pen core, a housing, and a pen body located in the housing, the housing includes a front housing and a rear housing, the pen body includes a first iron core and an iron core holder, the iron core holder is provided with a pen core clamp link, a second iron core, and a third iron core, coils are wound outside the first iron core and the second iron core, the first iron core is close to a pen tip of the pen core, the pen core is configured to pass through a center of the first iron core, and then is clamped by one end of the pen core clamp link.

Abstract: Disclosed is a passive electromagnetic fountain pen, which includes a pen core and a pen body, wherein the pen body includes a first iron core and an iron core holder, a pen core clamp link, a second iron core, a third iron core, an elastic component, a pressure regulating plate, and a first structure matched with the pressure regulating plate are disposed sequentially from front to back in the iron core holder, coils are wound outside the first iron core and the second iron core, the first iron core is close to a pen tip of the pen core, the second iron core is fixedly connected with the iron core holder, the pen core is configured to pass through a center of the first iron core, and then be clamped by one end of the pen core clamp link.

Abstract: Disclosed is a passive electromagnetic pen, which includes a pen core, a first iron core, and an iron core holder, wherein a coil is wound outside the first iron core, the first iron core is fixed to an end of the iron core holder close to a pen tip of the pen core, a second iron core, an elastic component, a pressure regulating plate, and a first structure matched with the pressure regulating plate are disposed in the iron core holder sequentially from front to back, and the pen core is configured to pass through a center of the first iron core, and then drive the second iron core to move; and the pressure regulating plate when in rotation is configured to be in surface contact with the first structure by a surface, so as to generate an axial displacement to change an axial displacement of the elastic opponent.