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. 20, 1987
Filed:
Aug. 12, 1985
Robert Bosch GmbH, Stuttgart, DE;
Abstract
To increase the resolution of digital words, for example eight-bit words, being supplied via a digital/analog (D/A) converter (2) to a closed control loop, the lowest-order bit (2a) is chopped with a duty cycle, that is, controlled pulse duration/pulse gap ratio, for accurate resolution of the entire word being transmitted. The D/A converter will provide an output of undulating or wavy form, which undulations or waves are averaged or integrated by a low-pass filter (5) or low-pass transmission characteristics of a controller (6) or the overall control loop (4-6-7-8-9-10-11-4) to which the analog signal is applied as a command signal. The system is particularly suitable for accurate control of a fuel supply control element, such as a throttle (9), in the induction pipe of an internal combustion engine using only eight-bit command words, by not transmitting the lowest-order bit in steady-state form but, rather, chopped with controlled duty cycle for conversion of the chopping effect into analog form in the D/A converter (2). The repetition frequency of the pulse duration modulation is suppressed by the low-pass filter or filter characteristics of the control loop.