Apparatus for selecting terminal equipment in telephone lines
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Dec 28, 1982
Grant Date -
N/A
app pub date -
Oct 17, 1979
filing date -
Oct 20, 1978
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
An exchange center is connected to telephone lines and a telephone and a data transmitter as terminal equipment are connected to the telephone lines. The data transmitter is actuated depending upon the polarity of DC voltage applied to the telephone lines. The telephone line is potentially opened by detecting the current of the telephone during the operation of the data transmitter. The impedance of the telephone line during the opening state is detected whereby the operation of the data transmitter is stopped by inverting the DC voltage applied to the telephone line and the telephone is predominantly communicated through the exchange center over the data transmitter.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully