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Ring detector circuit for telephone

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seenuvel

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can any help me with a circuit that detects rings in a Telephone.
 

DarkJedi

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Re: Ring detector

when the telephone rings certains voltages are send from the telephone lines. Once i messured them but it varies from country to country, i suggest you set up an osciloscope and start messuring the signals, then you will have a better idea of how to detect them.
 

lequoc

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Re: Ring detector

ic type
 

shwoo

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Re: Ring detector

Measuring ring voltage with an ordinary scope is not an easy task, as the
telephone line is balanced and most scopes grounded. You will need an
isolation transformer that can pass 16 to 20Hz.
For simple experiments, you can assume the voltage will be higher than
something like 50V. Detecting can be done with a bridge rectifier, say
four 1N4004 diodes, in series with a resistor and use an opto coupler to pass the ring status information to other logic circuit.
Isolation of telephone line with other logic or active circuit is important in many
cases unless you use a floating circuit.
S. H.
 

rogerynt

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Re: Ring detector

Ringer circuit that works for most of the European countries.

Rogerynt
 

zio_nneo

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Ring detector

use one transformer and then rectify the output of the transformer this will give you certain voltage at the output. But remember that before the transformer you have to use capacitor to block dc voltage.
 

sabeti_1990

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Re: Ring detector

hi
if U want listen the ring that image is OK
but if U want just detect line ring u can use that circuit until diode bridge & after that use 2 resistor or a npn transistor for ring detecting
:D
 

pranam77

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Re: Ring detector

Hello Seenuvel,
You can use this circuit which detects a ring signal and take the NPN transistor as a switch to be used to switch the further circuit as required. hope this will help.
 

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