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. 10, 2003
Filed:
Jul. 31, 2001
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A protective circuit for a series circuit of a power semiconductor and an inductive load, to which a freewheeling circuit of a freewheeling diode and a reverse polarity protection semiconductor switch connected in series is connected in parallel. The power semiconductor output stage may be switched on and off depending on a predetermined setpoint value with a pulse-width modulated control signal and the reverse polarity protection semiconductor switch may be made non-conducting via a charging pump when the polarity of the supply voltage is reversed. The destruction of components in the case of non-functioning of the freewheeling circuit may be avoided by monitoring a point in the freewheeling circuit of a freewheeling diode and a reverse polarity protection semiconductor switch or in the series circuit of load and power semiconductor output stage for a voltage or a current which appears if the freewheeling circuit is non-functioning, and by initiating the shut-off of the control of the power semiconductor output stage with this fault indicating voltage or current.