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:
Jan. 01, 1980
Filed:
Oct. 26, 1977
Walter Ruf, Korntal-Munchingen, DE;
Heinz Krauss, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A voltage divider across the interruptor switch contacts provides a measure of the high voltage produced before a spark occurs at the sparkplug. A Zener diode connected to the upper tap of the voltage divider breaks down when this voltage has risen a certain amount as the result of wear of the sparkplug electrodes that widen the gap. The Zener voltage breakdown causes a relay to lock in and to short-circuit a current-limiting resistor in the spark coil primary circuit that allows a higher voltage spark to be produced to assure proper firing of the sparkplugs with the wider gap. Another Zener diode is connected to the lower tap of the voltage divider to sound an alarm and to disable the ignition circuit when the high voltage at which sparks strike in the sparkplug rises to a value for which the insulation of the spark coil and its connection is not designed to withstand.