Coil, Choking

A coil of high self-induction, used to resist the intensity of or "choke" alternating currents. Any coil of insulated wire wound around upon a laminated or divided iron core forms a choking coil. The iron coil is usually so shaped as to afford a closed magnetic circuit. A converter or transformer acts as a choking coil as long as its secondary is left open. In alternating current work special choking coils are used. Thus for theatrical work, a choking coil with a movable iron core is used to change the intensity of the lights. It is in circuit with the lamp leads. By thrusting in the core the self-induction is increased and the current diminishes, lowering the lamps; by withdrawing it the self-induction diminishes, and the current increases. Thus the lamps can be made to gradually vary in illuminating power like gas lights, when turned up or down. Synonyms--Kicking Coil--Reaction Coil. IMG:8956969607833025625_132F97.jpg: Fig. 97. DIFFERENTIAL COILS AND PLUNGERS. IMG:8956969607833025625_132F98.jpg: Fig. 98. BISECTED COILS. 133    STANDARD ELECTRICAL DICTIONARY.