Telephonic communications – Diagnostic testing – malfunction indication – or electrical... – Testing of subscriber loop or terminal
Patent
1994-02-09
1996-05-28
Chin, Stephen
Telephonic communications
Diagnostic testing, malfunction indication, or electrical...
Testing of subscriber loop or terminal
379 1, 379 5, 379 10, 379 22, 379 24, 379 29, 379 30, H04M 124, H04M 308, H04M 322
Patent
active
055219594
ABSTRACT:
A microprocessor-controlled voltage source selectively provides to a telephone line either a DC or an AC voltage, prescribed characteristics of which are programmably adjustable, enabling test equipment to controllably condition and test the line with essentially any desired line conditioning voltage or signal waveform. A digital-to-analog converter (DAC) provides an output voltage having an amplitude that is digitally programmable. This output voltage is available to be applied either directly or through controlled amplifier circuitry to the line. In order to generate an AC signal having both an adjustable amplitude and waveform characteristic, the output of the DAC sets the amplitude for a combination of signals from a plurality of squarewave generators having programmable frequency characteristics. The output of the combining unit is coupled to a switched capacitor filter which filters the controllably-interrupted, digitally-controllable output voltage, (e.g., removes odd harmonics from the fundamental frequency of the desired waveform) and an adjustable smoothing filter, which is coupled to the switched capacitor filter and removes the `stairstep` transitions in the waveform associated with the operation of the switched capacitor filter. The output of the smoothing filter is coupled to an output amplifier which amplifies the AC waveform output of the adjustable smoothing filter.
REFERENCES:
patent: 4001559 (1977-01-01), Osborne
patent: 4611101 (1986-09-01), Walter
patent: 4634813 (1987-01-01), Hensley
patent: 4794632 (1988-12-01), Burton
patent: 4825458 (1989-04-01), Dash
patent: 4860332 (1989-08-01), Chism
patent: 4991196 (1991-02-01), Krebs
patent: 4995070 (1991-02-01), Shin
patent: 5003573 (1991-03-01), Agah
patent: 5018184 (1991-05-01), Abrams
patent: 5056131 (1991-10-01), Kanare
patent: 5062131 (1991-10-01), Kanare et al.
patent: 5063585 (1991-11-01), Shapiro
patent: 5195124 (1993-03-01), Ishioka
Barron Joseph
Knight Alex
Walsworth Richard L.
Chin Stephen
Harris Corporation
Shankar Vijay
Wands Charles E.
LandOfFree
Programmable source for supplying controllably variable AC/DC vo does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Programmable source for supplying controllably variable AC/DC vo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Programmable source for supplying controllably variable AC/DC vo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-793334