Dry contact may mean any of the following in electronics:
- No current: Dry contact can refer to a secondary set of contacts of a relay circuit which does not make or break the primary current being controlled by the relay. Usually some other contacts or device have the job of starting or stopping the primary current being controlled. For example, a reed relay matrix switch is normally switched with all contacts dry. After the contacts are all connected, a wire spring relay is energized and connects a supervisory scan point, or main switch, through which the primary current being controlled then flows. Dry contacts are primarily employed in 49 volt or less (low voltage) distribution circuits. See also Contactor
- No mercury: The wet contact of a Mercury-wetted relay gives certain operational advantages. Dry contacts means a relay that does not use mercury wetted contacts.
- Dry joint: A dry contact can be confused with a dry joint, which is a type of badly soldered joint in which the solder failed to wet the metal. These are liable to fail electrically. The term dry joint is also used less precisely to mean any sort of unsatisfactorily soldered joint.
Famous quotes containing the words dry and/or contact:
“There is not even silence in the mountains
But dry sterile thunder without rain
There is not even solitude in the mountains”
—T.S. (Thomas Stearns)
“There is hardly any contact more depressing to a young ardent creature than that of a mind in which years full of knowledge seem to have issued in a blank absence of interest or sympathy.”
—George Eliot [Mary Ann (or Marian)