Abstract: A yoke for a cathode ray tube has deflection coils and a plurality of trim magnets mounted thereon. A tubular shield of Mu-metal slides over the coil to suppress an electromagnetic field radiated therefrom. In one embodiment, the trim magnets are inside the shield so that it has to be removed in order to adjust the magnets. In another embodiment, the trim magnets are outside the shield, so that they may be adjusted without necessarily having to remove the shield. The shield greatly reduces outwardly directed electromagnetic radiation in the vicinity of the cathode ray tube which allegedly might produce a health hazard to an operator at a video monitor terminal.

Abstract: A flyback transformer operable over a broad frequency range is used as a regulated high voltage power supply. A ringless, layer-wound transformer is operated far below its natural resonant frequency in response to a pulse width modulator which may be synchronized with a video display in order to prevent beat frequency images in a video display. Diodes are coupled between the layers of windings to reduce the leakage inductance and stray capacitance. The supply is particularly suitable for TV or monitor use but not exclusively, so any apparatus requiring a regulated high voltage supply may use the invention.