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:
Aug. 01, 1989
Filed:
Nov. 17, 1987
Axel Schulz, Bickenbach, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
In order to provide a magnetic recording head with a broadband signal with minimum distortion from the reactances of wire connections and the like, a voltage controlled current source is used to feed equivalent circuits representing a magnetic head like the recording head in an output that is taken from that current source at a point that reflects the effect of the equivalent circuit to operate the controlled voltage source for providing the driving current for the recording head. Instead of a parallel coil and resistor combination in series with another resistor, the equivalent circuit can consist of another magnetic head of the same kind as the recording magnetic head but not used for recording. In practice differential or complementary cascode amplifiers are used for the voltage controlled current source at the signal input and differential or complementary final stage amplifiers are used for driving the recording head through a rotary transformer or broadband recording on tape. When the equivalent circuit is another magnetic head not used for recording, it may be convenient to drive it through a transformer, particularly when the controlled current source for which it provides a load is a differential amplifier.