December 20, 2021 By Bill Schweber Despite wide use of “soft” on/off switching, the traditional electromechanical switch is still often required or preferred and is available in countless versions.Switches are an integral, very necessary part of most electronic products. They have two broad roles: As power switches which, as their name indicates, cut the flow of power from the source, thus turning the unit or a load on and off; and as signal switches, which allow the user to indicate to the system what action is desired, such activating a function or connecting it into a system.Increasingly, the design tendency is to prefer soft switching over hard-wired physical switches. In this approach, a small, temporary contact closure is sensed by the system processor and software, or an image or button on a touch screen is sensed to indicate the desired action to the system (Figure 1). The processor, in turn, electronically cuts the flow of current via a load switch or other component to turn t...