What problems are encountered when switching computer generated graphics signals?
Most computers use switching power supplies, eliminating the need for heavy and bulky power transformers. Switching power supplies chop the mains voltage at high frequencies, transferring the electric energy via small, high frequency transformers. If the computer is not firmly grounded, very high voltages may appear on the chassis, outputs and everything using those power supplies. In normal cases this is not a serious problem, as one computer is connected to one monitor, and grounding one of them suffices to eliminate high voltages on the chassis. When switching the outputs of several computers to one monitor or vice versa, when all outputs are connected to the same switcher, high voltages, which may appear from several sources, can cause enormous damage, shorts and even fire. Switchers should target this problem. One of the ways to eliminate the problem is to leave all inputs and outputs of the switcher “floating” and have only the required connection link the signals and the ground
