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. 09, 1998
Filed:
Feb. 11, 1997
Francesco Pulvirenti, Acireale, IT;
Gregorio Bontempo, Barcellona P.G., IT;
Abstract
The purpose of the present invention is to protect the final transistor of a power actuator from short circuits and overloads with a completely integrated circuitry solution which would not influence the output impedance of the actuator and would permit having a limitation current constant and independent of the value of the output terminal of the actuator. A power actuator in accordance with the present invention incorporates a circuit for limitation of the maximum current delivered by the power transistor wherein the circuit comprises: (a) a network for detection of the current delivered by the power transistor which generates a first electrical signal proportional to said current, (b) a reference network generating a reference electrical signal, and (c) an operational amplifier which compares the first electrical signal with the reference electrical signal and which tends to inhibit the power transistor if the current delivered exceeds a certain threshold value and whose output terminal is coupled to the reference network in such a manner that the reference electrical signal depends on the voltage present at the amplifier output.