The capacitor of LED display is an energy storage container charge. It is closer to the metal sheet, and then every intermediate insulating substance consisting of two pieces relying. Press the insulating material is not the same, it can be made a variety of capacitors. Such as mica, ceramic, paper dielectric, electrolytic capacitors. In construction, it is divided into fixed capacitors and variable capacitors. Capacitors for DC resistance infinite, that has a DC blocking capacitor effect. Capacitors for AC resistance by AC frequency influence, namely the same capacity capacitor for alternating current frequency is not the same rendering is not the same capacitance.
When the switch S is closed, the free electrons of the capacitor anode LED display panel will be attracted to the power supply, and pushed to the negative plate above. Because the distance between the two plates of the capacitor with an insulating material so from the positive plate ran free electron will pile up on top of the negative electrode plate. The positive electrode plate by electron reductions will bring positive and negative plates will gradually add due to electron and a negative charge.
More about LED: http://social.singlescruise.com/index.php/classifieds/1342/1/small-pitch-led-display
http://leddisplay.shivtr.com/pages/leddisplaylighting
LED display between the two plates of the capacitor will have a potential difference when the potential difference between the power supply voltage is equal to the charge on the capacitor is stopped. If power is cut off at the moment, can still adhere to the charging voltage of the capacitor. He has been charged capacitor, if we use the wire to connect the two plates together, because between the plates presence of potential difference, electrons through a wire will return to the positive electrode plate until the potential difference between the plates is zero.
LED display higher the frequency of the capacitor, the alternating current blocking effect is reduced, i.e. small capacitance, contrary to the capacitor capacitance generated low-frequency alternating large. On the same frequency alternating current electricity. LED display capacity of the capacitor, the smaller the capacitance, the smaller the capacity, the greater the capacitance.