Telephone-speech-activity-detector


Posted on May 1, 2012

This circuit can be used in telephone lines for speech activity detection purposes. This detection is very useful in the case of half-duplex conversation between two stations-in the case of siroultaneous transmission of voice and data over the same pair of cables by the method of interspersion data on voice traffic, and also in echo suppressor devices. The circuit consists of a class-A amplifier to amplify the weak analog signals (25-400 mV).


Telephone-speech-activity-detector
Click here to download the full size of the above Circuit.

The IC1 which follows, is conneGted as a retriggerable monostable multivibrator with the TR2 discharging the timing capacitor C3, if the pulse train reaches the trigger input 2 of IC1 with period less than the time: THIGH ~ 1.1 R3C3. The output 3 of!C1 is active on when an analog or digital signal is presented at the output, and it drops to a low level, THIGH, seconds after the input signal has ceased to exist.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Led indicates logic states
Zero crossing detector
Automatic blind hooked up to existing projector screen using Arduino
12KV High Voltage Generator
Class D amp made easy with 555 timer IC
Lite + Xtall RX V9.0 Schematic
Subsumption Architecture
Clap Switch Circuit Project
Vibration Detector Circuit
Current Mirror for LEDs
Ripples in the Ether
Introduction
Phone to Microcontroller interfacing with DTMF
Transistor common emitter amplifier circuit
Battery discharge status indicator circuit
Cheap precision digital clock time base oscillation circuit
1B32 bridge sensor signal conditioner with multi-channel application circuit when the pressure sensor



Top