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. 17, 2014
Filed:
Oct. 08, 2012
Switch Bulb Company, Inc., San Jose, CA (US);
Ronald J. Lenk, Woodstock, GA (US);
John D. Grainger, Fremont, CA (US);
Switch Bulb Company, Inc., San Jose, CA (US);
Abstract
A light-emitting diode (LED) bulb has an LED within a shell. The LED bulb includes a driver circuit for providing current to the LED. The drive circuit has a thermal protection circuit, which includes a first positive thermal coefficient thermistor with a first switching temperature connected in series with a second positive thermal coefficient thermistor with a second switching temperature. The driver circuit includes a switch-mode power supply (SMPS) controller with an input pin and an output pin. The thermistors are connected to the input pin. When either thermistor temperature is above the respective switching temperatures, the thermal protection circuit causes the SMPS controller to produce a signal with a second duty cycle on the output pin. When both thermistor temperatures are below the respective switching temperatures, the thermal protection circuit causes the SMPS controller to produce a signal with a first duty cycle on the output pin.