Servomechanism
Servomechanism, automatic device used to correct the performance of a mechanism by means of an…
Systems and controls
Systems and controls
Superconductivity
Superconductivity, complete disappearance of electrical resistance in various solids when they are cooled below a characteristic temperature.…
Systems and controls
Electromotive force
Electromotive force, abbreviation E or emf, energy per unit electric charge that is imparted by an energy source, such as an electric generator or…
Systems and controls
Potentiometer
Voltmeter Voltmeter, instrument that measures voltages of either direct or alternating electric current on a scale usually…
Systems and controls
Rheostat
Rheostat, adjustable resistor used in applications that require the adjustment of current or the varying of resistance in an electric circuit. The…
Systems and controls
Alternating current
Alternating current, abbreviation AC, flow of electric charge that periodically reverses. It starts, say, from zero, grows to…
Systems and controls
Resistor
Resistor, electrical component that opposes the flow of either direct or alternating current, employed to protect,…
Systems and controls
Electric heater
Electric heater, device for heating rooms that converts electric current to heat by means of resistors that emit radiant energy. Resistors may…
Systems and controls
Lamp
Lamp, a device for producing illumination, consisting originally of a vessel containing a wick soaked in combustible material,…
Systems and controls
Electric current
Electric current, any movement of electric charge carriers, such as subatomic charged particles (e.g., electrons having negative charge, protons having positive charge), ions (atoms that have…