Persistence of vision refers to the optical illusion that occurs when
visual perception of an object does not cease for some time after the rays of light proceeding from it have ceased to enter the eye. When a person sees an object, its image remains in the retina of the eye for a time interval of 1/16th a second. This phenomenon is known as persistence of vision. This phenomenon is used in the LED POV Display to form images. We turn the LEDs on and off in such a way that the different images overlap each other forming letters and characters. So There is a motor spinning and it's speed is controlled by potentiometer in which I used high resistance wire from heating water rod.The Seven Array Led lights change at very short time ,so the image of Letter is formed