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:
Oct. 27, 1992
Filed:
Sep. 11, 1991
Jeffrey S Hawkins, Burbank, CA (US);
David P Tasky, Auburn Hills, MI (US);
Juhan Telmet, Sterling Heights, MI (US);
Detroit Diesel Corporation, Detroit, MI (US);
Abstract
A method and system are provided for controlling the energization of at least one glow plug in an internal combustion engine wherein a solid state drive circuit, including a semiconductor switch, is utilized for applying an energizing current to the at least one glow plug from a voltage source based on a control signal to electrically heat the at least one glow plug. The control signal is preferably a 50 Hz switched ground duty cycle signal from an electronic control module (ECM). Based on the duty cycle input, the drive circuit for each of the glow plugs supplies current from a main feed bus. A glow plug current monitoring circuit is provided for each of the glow plugs to detect whenever an open or short circuit condition appears in any of the glow plugs. The semiconductor device preferable is a current sensing type of MOSFET called a SENSEFET. Each SENSEFET internally monitors individual current draw of its respective glow plug to verify its proper operation. Upon detecting an out-of-limit condition of a glow plug, the drive circuit for the particular glow plug is disabled to protect the drive circuit and a diagnostic circuit in enabled to indicate this fault mode through an indicator lamp and starter inhibit relay driver circuit. Because the drive circuit for that particular glow plug is disabled, it does not sustain damage and resumes proper operation when a 'good' glow plug is installed for the 'bad' glow plug.