Electrical transmission or interconnection systems – Nonlinear reactor systems – Parametrons
Patent
1986-01-06
1988-04-12
Miller, Stanley D.
Electrical transmission or interconnection systems
Nonlinear reactor systems
Parametrons
307271, 307522, 307529, 328 27, 328 15, 328150, H03B 1900, H03K 1700
Patent
active
047377208
ABSTRACT:
A technique for generating predefined dual tone, multiple frequency signals composed of two non-harmonically related frequency components according to industry standards is disclosed. The frequencies of each tone pair are adjusted within a predetermined tolerance so that their peaks are time coincident within a minimum number of cycles. A sampling frequency for the adjusted frequency tone pair is selected to be synchronized with the occurance of the time coincident peaks of the tone pair. The adjusted frequency tone pair are summed and then sampled at the selected sampling frequency and stored in a table in a digital memory. The digital memory contains a plurality of tables, one for each sampled summed tone pair, and the tables are variable in length being optimized for the summed tone pair stored in the table. In order to generate a desired dual tone, multiple frequency signal, the table in memory containing the desired summed tone pair is bidirectionally scanned at a scanning rate equal to the sampling frequency for that tone pair to read out the samples in repeating sequence. The samples are then converted to an analog signal approximating the desired dual tone, multiple frequency signal.
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Emanuel Peter M.
General Electric Company
Lenihan Thomas F.
Miller Stanley D.
Rasmussen Paul J.
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