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. 19, 2001
Filed:
Jul. 09, 1999
Giancarlo Casellato, Turin, IT;
C.R.F. Societa Consortile per Azioni, Orbassano, IT;
Abstract
A circuit device is described for controlling the piloting voltage applied to the solenoid of an electromagnet associated with an electric starter motor of an internal combustion engine of a motor vehicle. This control device comprises: a voltage generator operable selectively to provide a first predetermined reference voltage corresponding to a desired speed of displacement of the movable core coupled to the solenoid, and a second reference voltage of lower value than the first; a sensor operable to provide a signal indicative of the current flowing in the solenoid; an amplifier having a variable gain with its input connected to this sensor; and a summing device with first and second inputs connected to the generator and the output of the amplifier respectively, and having an output connected to the solenoid. A control and calibration circuit controls the generator when the control device is activated, initially to generate a low reference voltage and then to provide the amplifier with a signal such that its gain increases until the voltage applied to the solenoid reaches a predetermined maximum value, and the signal at the output of the amplifier corresponds to the voltage drop across the resistance of the solenoid; it finally maintains the gain of the amplifier at this value and controls the generator to generate the first reference voltage.