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:
Mar. 04, 1980
Filed:
May. 30, 1978
Dustin J Becker, Rocky River, OH (US);
Lorain Products Corporation, Lorain, OH (US);
Abstract
An apparatus for generating a selected one of a plurality of ringing frequencies utilizing a single frequency source. A first counting means is utilized to divide the source frequency by a first predetermined integer to generate a series of address signals at a rate proportional to the selected ringing frequency. A read only memory is responsive to the address signals for generating a series of values representing points along a sine wave form such that, as the first counting means continuously cycles to a maximum count total equal to the number of values stored in the read only memory, the sine wave form is repetitively generated. If the source frequency is not an integer multiple of the selected frequency, the first integer is selected to generate the closest higher frequency and a second counting means is utilized to increase the time required for the first counting means to generate all of the address signals for one cycle of the sine wave form. The second counting means divides the first counting means output frequency by a second predetermined integer to generate signals to disable the first counting means for at least one count each. The second integer is selected to obtain the number of missed counts of the first counting means which will result in an actual cycle time as close to the selected cycle time as possible.