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. 16, 1984
Filed:
Sep. 07, 1982
Rudiger Ratzel, Buhl, DE;
Erich Schneider, Kirchheim, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A logic circuit (34) is provided for preventing the application of energizing voltage to a positioning motor in the case of a circuit failure in the drivers stage of a control system. An equality gate provides a signal to each AND gate corresponding to a failure detection criterion whenever signals of the same level are present at the respective transistors controlling operation of the motor into opposite directions. At one AND gate a signal is provided if either of the transistors is conducting, indicating a failure if there is no control signal. At the other AND gate a signal is provided if either terminal of the motor is connected to energizing potential, likewise indicating a failure if no control signal at a transistor input is present. If either AND gate responds the equivalent of a control signal is applied to a pair of diodes to both of the transistor inputs, thereby blocking the motor.