Title:
Delay-action device employing thermionic valves
United States Patent 1552321


Inventors:
Norman, Lea
Application Number:
US52838922A
Publication Date:
09/01/1925
Filing Date:
01/11/1922
Assignee:
Norman, Lea
Primary Class:
Other Classes:
315/355
International Classes:
H03K17/288
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