Title:
SIGNAL CONTROL AMPLIFIER IN TELEPHONE LINE-FEED CIRCUIT
Document Type and Number:
Japanese Patent JPS61113349
Kind Code:
A
Abstract:
A signal limiting amplifier includes interstage limiting devices to restrict the range of output voltage signals. The devices are base-emitter circuits of transistors, one of which operates in response to one polarity of signals and has its collector terminal unconnected, and the other of which operates in response to the other polarity of signals and has its collector circuit connected (when limiting) to operate an appropriate utilization circuit. In one embodiment, the limiting amplifier is applied as a common mode feedback amplifier in a telephone line feed circuit, and the limiter signal is used to limit large longitudinal signals on a customer line and to power down the line feed circuit in the event the limited signals persist beyond a certain interval.
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Inventors:
FURANKU FUIRITSUPU CHIYUHII JI
Application Number:
JP21815285A
Publication Date:
May 31, 1986
Filing Date:
October 02, 1985
Export Citation:
Assignee:
AMERICAN TELEPHONE & TELEGRAPH
International Classes:
H04M3/18; H04M19/00; (IPC1-7): H02H9/04; H04M3/18
Domestic Patent References:
| JPS5862906A | 1983-04-14 |
Attorney, Agent or Firm:
Masao Okabe