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:
Aug. 31, 1976
Filed:
Apr. 21, 1975
Daniel A Wisner, Milan, MI (US);
Andrew S Mihalik, Jr, Northville, MI (US);
Burroughs Corporation, Detroit, MI (US);
Abstract
An improved switching regulator converts an unregulated DC voltage into a regulated DC output voltage and maintains regulation over the entire range from maximum load current through zero load current. The improved regulator employs a plurality of series switching paths connected between the unregulated DC input and a summing node at a filter capacitor output. Each series switching path includes a power switching element, a catch diode and a series inductor. The other end of the summing node is connected through a current limiting circuit to the DC regulated output, and at least a portion of the voltage at the summing node is fed to a voltage error amplifier and used to control the duty cycle of the series switching elements. Feedback from the current limiting circuit can override the voltage error amplifier control should the maximum current limit be exceeded. The switching control means employs pulse-width modulation for adjusting the duty cycle of the series switching elements, and the technique of pulse-width modulation employed in the present invention is of the constant frequency, variable 'ON' time variety, as known in the art. The switching element control means utilizes a selecting means whereby different ones of the switching elements in different ones of the series switching paths are sequentially selected such that the selected series switching element is always turned on into a non-conducting inductor and a fully-recovered catch diode so as to minimize or eliminate the power loss associated with switch turn-on; the noise usually associated with switching regulators; and the turn-on transient which is often propagated into the supply line in the switching regulators of the prior art, thereby allowing highly efficient and reliable regulation to be maintained at very low values or even no value of load current.