How To Build Simple Electronic Stereo Signal Detector And Selector Circuit

This circuit allows only stereo broad·

casts to be outputed by a tuner using

either a 1310 or 3090 type stereo

decoder chip. ln both cases the stereo

beacon driver is used to switch the

audio output of the tuner. When a

stereo signal is being received the

beacon driver output is low which

turns the O1 and energises reed

relay RL1. The two contacts which

switch the output .lines are closed

and the stereo signal is available at

the tuner output sockets. RL1 can be

any reed relay with a coil resistance

greater than 120 ohms and two norm-

ally open contacts.

Simple Stereo Signal Detector Circuit Diagram


Another Cool Circuit

A device to

switch the audio from a

stereo tuner only when a Stereo sig-

nal is being received.

Two CMOS NAND gates and two

transistors are employed One of the

inputs from each gate is connected

together and to the indicator output

of the decoder lC.

The other gate inputs are connected

t0 the emitter’s of Ol and O2 respect-

ively, by means of the feedback resis-

tors R2 and R4. On reception of a

stereo signal the

indicator output of

the decoder goes high and the

feedback resistors bias the gales

=nto the linear region passing the

signal On reception of a mono

signal or interstation noise, no

signals pass through the gates, the

circuit providing a ‘mute' function.

Article Written By Swagatam

Swagatam is a blogger at

Last updated on 25-07-2016 110 0

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