Abstract: A choke coil for preventing harmonic distortions having a plurality of laminated iron core sheets formed into a core. A first coil is wound around a first limb of a first core, and a second coil is wound around a first limb of a second core. A third coil is wound around the second limb of both the first core and the second core, and the second core is disposed within the magnetic circuit of the first magnetic core. The iron core sheets have embossments formed on a front and back side for fitting the iron core sheets together. The embossments have longitudinal sides formed orthogonally to the direction of magnetic fluxes in the core, and may be inwardly inclined to face each other.

Abstract: A choke coil for preventing harmonic distortions, used with home-use and industrial electronic apparatuses, is designed to reduce the apparatus size, reduce leakage fluxes and realize superior high-frequency characteristics. In order to achieve this object, there is provided a choke coil comprising a first magnetic core and a second magnetic core making up a closed magnetic circuit or an open magnetic circuit, a first coil, a second coil and a third coil, wherein the first coil is wound on the first magnetic core, the second coil is wound on the second magnetic core, and further the third coil is wound in such a manner as to cover the first magnetic core and the second magnetic core, and an inductance value required for preventing harmonic distortions is secured by the magnetic circuit configuration. At the same time, the function of a common-mode choke coil is provided to increase a coupling coefficient and reduce the system size and leakage fluxes.

Abstract: A compact ignition apparatus for a burner, which rectifies the commercial power source and energizes a high-voltage transformer via a transistor blocking oscillator circuit, and in which the high-voltage transformer is provided with a control circuit for controlling the output of the transformer to a constant value against any fluctuation of the input to the transformer, whereby a secure ignition is provided.