The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 1994
Filed:
Oct. 13, 1992
Randy J Longsdorf, Chaska, MN (US);
Richard L Nelson, Chanhassen, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
A protection circuit is provided for protecting sensitive electrical field instruments from a transient voltage strike and for ensuring that the instruments will meet safety approval during high potential voltage testing. The first and second wires of a two-wire circuit are connected to a first and second terminal respectively. A first surge arrestor electrically couples a first path between the first and second terminal. An impedance and a transient suppressor are connected in series and electrically couple a second path between the first and second terminal. The second path is coupled in parallel with the first path between the first and second terminal and is coupled closer to the internal components of the electrical instruments to be protected than is the first path. A second surge arrestor is electrically coupled between the second terminal and ground, and has a higher voltage breakdown potential than the first surge arrestor.