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:
Sep. 19, 1978
Filed:
Mar. 18, 1977
Ian Wilfrid Buckner, Reading, GB;
Plessey Handel und Investments AG, Zug, CH;
Abstract
A frequency-comparing device is arranged when in its no-output condition to respond to a pulse from a first one of two inputs by supplying a predetermined one of the two outputs until a pulse of another sequence arrives to terminate this output, whereafter the pulse next arriving will restore the same output if that pulse comes from the first input whereas if that pulse is one of the second input it will initiate the other output. Assuming that the pulse sequence from the first input has a frequency proportional to the speed of a motor unit and the pulse sequence from the second input consists of time pulses produced for example by a reference oscillator and that the output initiated by the arrival of a pulse from the first input is used as a drive-low input for the speed regulation unit of the motor while the other output constitutes a drive-high input for the same unit and that furthermore the pulse frequency derived from the motor speed is arranged to be equal to that derived from the reference oscillator when the motor runs at its desired speed, it will be found that when the motor speed is higher than the desired speed two pulses from the first input will from time to time occur within the interval between two consecutive pulses from the second input.