Signal switches activate or deactivate a signal once an event has occurred. A signal switch provides high-performance, low-power replacements for standard bus-interface devices when signal buffering is not required. There are many types of signal switches. Examples include sensor switches, electrical switches, and indicator switches. Sensor switches are devices that sense and convert physical information about the environment into a readable form such as analog voltage, current, charge, or frequency. A sensor switch has the capability to satisfactorily pass analog signals as well as digital signals. Electrical switches are devices that include left- and right-turn signals for up to 8 lamps per side, and four-way flashing for up to 16 lamps. An electrical switch has two pieces of metal called contacts that touch to make a circuit, and separate to break the circuit. An indicator switch correlates time and voltage readings from the electromechanical actuators to indicate exactly where the tabs are at all times. An electrical relay is an electrical device that enables a current flowing through it in one circuit to switch on and off a current in a second circuit. An electrical relay includes an electromagnet which is a temporary magnet made by coiling wire around an iron core. Other types of signal switches are commonly available.