A name for the induction-coil as adapted for the display of the electric spark.

a type of induction coil invented by Tesla, employing a spark gap in place of an interruptor and capable of producing an intense high-frequency…

an electrical inductance coil which is spirally wound so as to be flat, or has a diameter significantly greater than its axial length.

an inductance coil in which the turns are wound obliquely so as to give a criss-cross pattern, reducing capacitive effects.

(see quots.).

Used attributively with reference to various devices and theories invented by Helmholtz.