what's whiteboard in irish.The principle of the resistive film technology is that the basic structure of the electronic whiteboard is composed of a multilayer film, including a horizontal wire resistive film, an insulating mesh, a conductive film, an insulating mesh, a vertical resistive film, etc., and the combined film has the same size as the used area. The working principle is to add a fixed voltage to the resistive film. Under the action of no external force, the conductive film does not contact the resistive film, no voltage is measured, and there is no information reaction of the positioning. When a hard object is pressed at a certain point of the resistive film, the current is read by the test circuit through the conductive film, just like a point test from a potentiometer to a varying voltage, which is related to the position of the touch point, according to the level The voltage read in the vertical direction can be converted to the X and Y direction of the touch point . The resistive touch screen is a grid scanning implementation, which is characterized by the fact that when an object is pressed against the surface of the film, it can reflect the position where the object is pressed. Analysis of advantages and disadvantages of technology: Advantages: 1. Positioning is relatively accurate. 2 , no special pen, can do touch operation disadvantages: 1 , writing requires a certain strength 2 , can not do large area mainly used manufacturers: United States: Polyvison , Interactive Techtwo: electromagnetic induction electromagnetic induction type of work is: electromagnetic waves can be The air is transmitted by an air and an insulating object. The electromagnetic induction type is composed of a receiving coil film that can emit electromagnetic waves and is arranged in two horizontal and vertical directions. The size of the film is the same as the display area. The principle of positioning is that the pen that emits electromagnetic waves emits electromagnetic waves in an intermittent manner. When the pen is close to the film of the receiving coil, the electromagnetic waves emitted by the pen are sensed on the coil. The higher the electromotive force induced by the coil group closest to the pen, the electromotive force induced according to the horizontal direction and the vertical direction can be obtained by calculation.