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:
Apr. 21, 2015
Filed:
Feb. 15, 2012
Masaaki Shimada, Niiza, JP;
Yoshimichi Tadamasa, Niiza, JP;
Masaaki Shimada, Niiza, JP;
Yoshimichi Tadamasa, Niiza, JP;
Sanken Electric Co., Ltd., Saitama, JP;
Abstract
A constant current power supply apparatus is provided which can drive a load with a constant current, even if the circuit configuration is such that a time delay is generated in the feedback control of a converter, or the like. An FB period restricting circuit including an ON generation circuit, OR circuit, inverter, and PMOS restricts the period during which an FB signal is fed back, to the logical sum of the ON period of an SW signal for driving an LED array on and a replenishment period generated by the OR circuit based on the SW signal. An FB signal generation circuit including a differential amplifier, NMOS, reference voltage, capacitor, and shunt regulator generates, in the replenishment period other than the ON period of the SW signal, an FB signal corresponding to an output current having flown through the LED array during the ON period of the SW signal.