Emitter

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An emitter is an device used to emit any signal, beacon, light, odor, liquid, fragrance, or the like. Also called as dripper is a device used in drip irrigation.

[edit] Drip irrigation

An emitter also called as dripper is a device used in drip irrigation to transfer water from a pipe or tube to the area to be irrigated. Typical emitter flow rates are from 0.16 to 4.0 US gallons per hour (0.6 to 16 L/h). In many emitters, flow will vary with pressure, while some emitters are pressure compensating. These emitters employ silicone diaphragms or other means to allow them to maintain a near-constant flow over a range of pressures, for example from 10 to 50 psi (70 to 350 kPa).

Some of the more notable manufacturers of emitter are:

Jain irrigation Systems (Jalgaon, India)
Chapin Watermatics (New York, U.S.A.)
Eurodrip (Greece)

[edit] Electronics

In vacuum tube technology, the emitter is another name for the cathode, which emits electrons through thermionic emission or field emission.

In transistor technology, the emitter is the analog of the vacuum tube cathode, though the current flow through it may be either positive or negative, depending on the type of transistor.

An emitter may refer to an infrared LED used to emulate a remote control. It emitter can also be wired into the integrated receiver/decoder of a satellite TV unit, so that it can operate a VCR to record a TV show when selected from the program guide. The wired emitter is stuck with an adhesive to the front of the VCR, and mimics the signals of the remote, eliminating the need to set the VCR separately.