Umschalt

Umschalt is a German term from um- (re-, again-) and schalten (to switch). In technical usage it denotes the process or device by which a system changes from one state, input, or mode to another. The more common nouns used in practice are Umschaltung (the act of switching or changeover) and Umschalter (a switch or selector device). Umschalt as a stand‑alone nominal form is less frequent in everyday language but appears in compound terms and in specialized texts.

In electrical engineering and power systems, Umschalt refers to changeover between signals or power sources. Examples include automatic changeover from mains to backup power, or the operation of selector switches that route a signal to one of several outputs. Devices designed for Umschaltung are often called Umschalter, Wechselschalter, or changeover switches and may be implemented as mechanical, electro-mechanical, or relay-based systems. In control circuits, Umschaltung is a fundamental operation that ensures the correct path for control or measurement signals.

In computing and information technology, Umschalt describes the act of switching between modes, languages, input methods, or data channels. User interfaces commonly implement Umschalten as a toggle action, and software terminology may use Umschalten or Umschaltung interchangeably with English terms like switch or toggle. Outside technical contexts, the term also appears in German media and documentation to denote a changeover process in machinery, transport systems, and audio/video equipment.

Note: The standard noun for the device is Umschalter; Umschaltung is the process. The variant Umschalt is encountered in some texts but is less common as an independent noun overall.