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. 29, 1997
Filed:
Dec. 21, 1995
Brendan P Kelly, Stockport, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A respective power semiconductor switch (M1, M2, M3) is provided for each ignition coil (20) of an internal combustion engine. Each such switch (M1, M2, M3) has a first main electrode (C) for coupling the primary winding (20a) of the associated ignition coil (20) to a first voltage supply line (1), and a control electrode (G) coupled to an respective ignition control line (Ign1, Ign2, Ign3) for rendering these switches (M1, M2, M3) conducting in a given sequence. A further semiconductor device (M4) has first and second main electrodes (d and s) coupled between second main electrodes (E) of the power semiconductor switches (M1, M2, M3) and a second voltage supply line (2), and a control electrode (g) for a drive signal controlling the current flow through the device (M4). A current sensing arrangement (Rs) senses the current flowing through this further device (M4). A control device (30) common to the switches (M1, M2, M3) of the coils (20) controls the drive signal to the control electrode (g) of the further device (M4) to limit the current through this further device (M4) to a predetermined value and then to turn off this further device (M4) so as to render a conducting one of the switches (M1, M2, M3) non-conducting to initiate sparking in the cylinder associated with that one switch. Sophisticated logic and control functions can be integrated with the common control device (30). The complex impedance of the ignition coil (20) can be isolated readily from the control loop of the further device (M4) and control device (30) by the switches (M1, M2, . . . ) operating in cascade with the further device (M4).