Title:
TWO-WIRE GAIN LINE OSCILLATION PREVENTING CONTROL SYSTEM
Document Type and Number:
Japanese Patent JPH01155723
Kind Code:
A
Abstract:
PURPOSE:To surely prevent oscillation by providing an oscillation detection section to a 2-wire gain line and blocking a signal when it is detected and identified the signal level is over the oscillating level so as to send a silence signal. CONSTITUTION:If any oscillation takes place, the signal level is increased and reaches the oscillation level or over, then it is detected that the oscillation level is exceeded at one or both the oscillation detection sections 33, 34. Thus, a silence pattern is sent in place of the signal. Thus, the output signal of D/A converters 31, 32 is a silence signal to prevent the oscillation. If communication is started while the silence pattern is sent, the level of the digital signal reaches the communication minimum level or over and it consecutive for a prescribed time, and it is detected by the oscillation detection section 33, 34, then the voice signal is passed without modification.
Inventors:
NAKADE HIROSHI
TAKEO HIROSHI
TAKEDA SATOSHI
YAMAZAKI HIROSHI
MIURA NORIHISA
TAKEO HIROSHI
TAKEDA SATOSHI
YAMAZAKI HIROSHI
MIURA NORIHISA
Application Number:
JP31231887A
Publication Date:
June 19, 1989
Filing Date:
December 11, 1987
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
H04B3/20; H04M3/40; (IPC1-7): H04B3/20; H04M3/40
Attorney, Agent or Firm:
Shoji Kashiwaya (1 person outside)