Con*trol"ler (?), n. [From control, v. t.: cf. F. controleur.]
1.
One who, or that which, controls or restraines; one who has power or authority to regulate or control; one who governs.
The great controller of our fate
Deigned to be man, and lived in low estate.
Dryden.
2.
An officer appointed to keep a counter register of accounts, or to examine, rectify, or verify accounts. [More commonly written controller.]
3. (Naut.)
An iron block, usually bolted to a ship's deck, for controlling the running out of a chain cable. The links of the cable tend to drop into hollows in the block, and thus hold fast until disengaged.
© Webster 1913
Con*trol"ler, n.
1. (Elec.)
Any electric device for controlling a circuit or system; specif.:
(a)
An electromagnet, excited by the main current, for throwing a regulator magnet into or out of circuit in an automatic device for constant current regulation.
(b)
A kind of multiple switch for gradually admitting the current to, or shutting it off from, an electric motor; as, a car controller for an electric railway car.
2. (Mach.)
A lever controlling the speed of an engine; -- applied esp. to the lever governing a throttle valve, as of a steam or gasoline engine, esp. on an automobile.
© Webster 1913