Suche

coherer Definition

coherer Bedeutung

Ergebnisse der Bewertung:
112 Bewertungen 5

 

Einfach einen Begriff in der Tabelle rechts anklicken um weitere Übersetzungen in dieser Sidebar zu erhalten.

The coherer is a primitive form of radio signal detector used in the first radio receivers during the wireless telegraphy era at the beginning of the 20th century. Its use in radio was based on the 1890 findings of French physicist Edouard Branly and adapted by other physicists and inventors over the next ten years. The device consists of a tube or capsule containing two electrodes spaced a small distance apart with loose metal filings in the space between. When a radio frequency signal is applied to the device, the metal particles would cling together or "cohere", reducing the initial high resistance of the device, thereby allowing a much greater direct current to flow through it. In a receiver, the current would activate a bell, or a Morse paper tape recorder to make a record of the received signal. The metal filings in the coherer remained conductive after the signal ended so that the coherer had to be "decohered" by tapping it with a clapper, such as a doorbell ringer, each time a signal was received, thereby restoring the coherer to its original state. Coherers remained in widespread use until about 1907, when they were replaced by more sensitive electrolytic and crystal detectors.

Vokabelquiz per Mail: