Moisture-tight wound ferrite toroidal core with resin envelope

摘要

A ferrite toroidal core is inserted into an annular trough enclosed by a cap with a winding applied about the trough member which is then sealed by an envelope of resin. The trough member includes resilient tabs extending internally of at least one mutually concentric trough wall, the tabs having their free edges disposed against the toroidal core so that the core is fixed and centered within the trough and so that an air cushion is provided between the core and the trough wall.