Title: Electromagnetic interference suppression system for electrical equipment

Abstract: Method and apparatus for suppressing differential and common mode conducted electromagnetic interference emission in electrical equipment powered from a grounded A.C. line source without creation of a shock hazard. Differential mode interference is suppressed by connecting a capacitor across the power lines and common mode interference is suppressed by an inductor inserted in the ground lead, both positioned within the equipment case or housing. The capacitor and inductor can have substantially fixed values for a wide range of equipment. In the preferred embodiment, the inductor is constructed by winding a few turns of the ground lead itself through a high permeability, ferrite toroid positioned within the case or housing.

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Inventors: King, William M. (Santa Monica, CA, US)
Roberts, Jack V. (Los Angeles, CA, US)

Application Number: 797466
Filing Date: 1977-05-16
Publication_date: 1979-03-20
Assignee:
Primary Class(es): 333/181 307/105, 333/12, 333/185
Other Classes:
US Patent Ref:

2015667	Oct, 1935	Fleming et al.	307/105.
2165886	Jul, 1939	Daniel	307/105.
2321376	Jun, 1943	Finch	333/76.
2419907	Apr, 1947	Mole	333/12.
2705759	Apr, 1955	Taggart	307/105.
3373301	Mar, 1968	Black	307/105.
3548347	Dec, 1970	Miller et al.	333/70.
3555466	Jan, 1971	Bernstein	333/76.
3854107	Dec, 1974	Tuchto et al.	333/79.

Other Refs:
Primary Examiner: Smith, Alfred E.
Assistant Examiner: Nussbaum, Marvin
Attorney: