page_title: Switch
section_title: Electronic switches
hierarchical_section_title: Switch / Electronic switches
caption_attribution_description: English: Three tactile switches. Ruler scale is in inches. The left one is surface mount. Also, note that the leads of the switches are in varying states of tarnish; far left is least tarnished, while the one on the right is quite tarnished. Deutsch: Drei Sprungkontakt-Taster. Zölliger Maßstab zu Vergleichszwecken. Links eine Ausführung zur Oberflächenmontage. Durch unsachgemäße Lagerung sind die versilberten Anschlussdrähte durch den Einfluss von Schwefelverbindungen von links nach rechts zunehmend angelaufen. Beim Mittleren und Rechten gut zu sehen, dass jeweils das Blech, dass die Steckkontakte bildet auf beiden Seiten gerade durchgeht und über einen Druck auf den Knopf in der Mitte verbunden wird. Es gibt also eigentlich nur zwei Anschlüsse
context_page_description: In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow.
  Switches are made in many different configurations; they may have multiple sets of contacts controlled by the same knob or actuator, and the contacts may operate simultaneously, sequentially, or alternately. A switch may be operated manually, for example, a light switch or a keyboard button, or may function as a sensing element to sense the position of a machine part, liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as the toggle switch, rotary switch, mercury switch, pushbutton switch, reversing switch, relay, and circuit breaker.
context_section_description: A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device to perform switching—often a silicon-controlled rectifier or triac.
  The analogue switch uses two MOSFET transistors in a transmission gate arrangement as a switch that works much like a relay, with some advantages and several limitations compared to an electromechanical relay.
  The power transistor(s) in a switching voltage regulator, such as a power supply unit, are used like a switch to alternately let power flow and block power from flowing.
  Many people use metonymy to call a variety of devices "switches" that conceptually connect or disconnect signals and communication paths between electrical devices, analogous to the way mechanical switches connect and disconnect paths for electrons to flow between two conductors. Early telephone systems used an automatically operated Strowger switch to connect telephone callers; telephone exchanges contain one or more crossbar switches today.
  Since the advent of digital logic in the 1950s, the term switch has spread to a variety of digital active devices such as transistors and logic gates whose function is to change their output state between two logic levels or connect different signal lines, and even computers, network switches, whose function is to provide connections between different ports in a computer network. The most widely used electronic switch in digital circuits is the metal–oxide–semiconductor field-effect transistor (MOSFET).
  The term 'switched' is also applied to telecommunications networks, and signifies a network that is circuit switched, providing dedicated circuits for communication between end nodes, such as the public switched telephone network. The common feature of all these usages is they refer to devices that control a binary state: they are either on or off, closed or open, connected or not connected.
caption: Three push button switches (Tactile Switches). Major scale is inches.
exif: {}