http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CA-1142280-A
Outgoing Links
Predicate | Object |
---|---|
assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_e9ec95f75bc5dcc8f2c6f36fd3ee1ca6 |
classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/H04Q1-453 |
classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H04L27-26 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H04Q1-45 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/H04Q1-453 |
filingDate | 1979-12-05-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
grantDate | 1983-03-01-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_e665ce8b2d4c353a3ea976ae6c033f5f |
publicationDate | 1983-03-01-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
publicationNumber | CA-1142280-A |
titleOfInvention | Detector for multifrequency signals |
abstract | "DETECTOR FOR MULTIFREQUENCY SIGNALS" Abstract: Multifrequency signals, as used in telephone communications systems for example, are detected by filtering an incoming signal in a plurality of filters having passbands corresponding to the possible frequencies in the signal. The filter outputs are each compared by comparators, with a threshold level dependent on the true RMS value of the incoming signal. Relative gains are adjusted such that the peak amplitude of a single frequency incoming signal, midway between the center frequencies of two adjacent filters, just corresponds to the threshold. The pulsed output of the comparators is evaluated to determine whether two and only two tones are present and whether the pulses are present for a sufficient portion of a sampling interval and for at least a minimum number of intervals. |
priorityDate | 1978-12-07-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 22.