Rectifier

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, copper and selenium oxide rectifiers, semiconductor diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motors have been used. Early radio receivers, called crystal radios, used a "cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or "crystal detector".

Rectifiers have many uses, but are often found serving as components of DC power supplies and high-voltage direct current power transmission systems. Rectification may serve in roles other than to generate direct current for use as a source of power. As noted, detectors of radio signals serve as rectifiers. In gas heating systems flame rectification is used to detect presence of a flame.

Reconcilee

Reconcilee is a neologism for the Czech word “upravenec” (pl. “upravenci”) which denotes an émigré from Communist Czechoslovakia who “reconciled” his or her relationship with the Communist régime.

The origins

From 1948 until the end of the régime, unauthorized migration from Czechoslovakia was a crime. Between 1945 and 1987 172,659 people went into exile. After the Helsinki Accords, the Communist establishment wished to show some kind of mitigation of the thus far harsh attitude towards émigrés. Directive No. 4/1977 Official Journal of the Czech Socialist Republic, On Reconciliation Legal Relationships of Czechoslovak Socialist Republic to Citizens Who Stay Abroad Without a Permit of Czechoslovak Authorities, was adopted. Hence the term “upravenec”.

Categories

In 1980 there were 115,000 émigrés. Directives stipulated two categories of reconcilees:

Rectifier (disambiguation)

The word rectifier refers to the general act of straightening. It may refer to:

See also