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. 12, 1978
Filed:
Dec. 27, 1976
Michael Alan Ford, Maidenhead, Buckinghamshire, GB;
Other;
Abstract
A tunable electrical filter is disclosed wherein an RC (resistor-capacitor) network comprising a plurality of switchable capacitors among the components determining the time constant of the filter provides a given minimum value of filter time constant and, therefore, a given minimum bandwidth, when all the capacitors are continuously connected in the network. Each capacitor is coupled to the network through the output means of an electronic switching means. A pulse generator connected to the input means of said switching means provides a train of pulses having an adjustable ON-time to OFF-time ratio. When all the capacitors are periodically switched by the output of the pulse generator, the effective filter time constant increases from said given minimum value as the ON-time compared with the OFF-time decreases. The pulse generator is provided with control means for adjusting the ON-time to OFF-time ratio. Operation of the control means will, therefore, enable the filter to be tuned within a predetermined range.