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. 12, 1990
Filed:
Feb. 22, 1989
Robert W Deutsch, Sugar Grove, IL (US);
John Aseltine, Buffalo Grove, IL (US);
Stephen G Oller, Schaumburg, IL (US);
Daniel D Prochaska, Sr, North Lake, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
Diagnostic fault test system and circuit sequentially tests a plurality of drivers (12) and their associated solenoid loads (13). Control signals (PM, SM) are provided to the drivers by a computer controller (11) to achieve desired solenoid actuation. The controller temporarily alters the control signals such that all of the drivers are forced into an on or off state for a first time period (t.sub.A or t.sub.B). After a delay (t.sub.Don or t.sub.Doff) a signal (V.sub.M) associated with each driver stage is monitored to determine if the driver and its load are operating properly. Then the controller resumes normal control of the drivers. The duration of the forced on/off state is short enough so as not to cause a change in the actuated/nonactuated state of the solenoid loads. Each monitored signal from the driver is sequentially compared to a high and low threshold (50, 51) to indicate either proper operation or the identification of one of two different types of fault which may occur. Drivers are preferably tested in both on and off states for proper operation and identification of a total of four different possible faults. Present system allows rapid testing of all drivers and their loads by use of a common transient setting delay time. Accuracy is improved since driver switching during fault monitoring is not permitted. Fewer components are needed since a single comparator (18) is used to sequentially compare each monitored signal for each driver with both high and low thresholds. Also, an indication of what type of fault is provided rather than just providing an indication that some fault exists.