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:
May. 28, 1991
Filed:
Sep. 15, 1989
Isaac L Flory, IV, Blacksburg, VA (US);
Joe A Nuckolls, Blacksburg, VA (US);
Hubbell Incorporated, Orange, CT (US);
Abstract
A disabling circuit for deactivating a high pressure sodium lamp starting and operating circuit when the lamp exhibits end-of-life cycling includes a normally closed thermal switch connected to the starting and operating circuit is inoperative, the switch having contacts which open in response to an elevated temperature. A heating element is connected in parallel with the lamp so that the voltage across the lamp is applied to the heating element. The heating element is supported in a selected heat conducting relationship with the thermal switch so that a predetermined elevated temperature is reached and the contacts are opened only after the dissipation of an amount of energy resulting from repeatedly high lamp open-circuit voltage accompanying end-of-life cycling.