[email protected]

#1130

I'm a beginner in electronics and I would like to know if there are 
any optoisolators out there that would work with audio. I want to 
record my phone conversations (4 seperate lines) but without 
grounding the actual lines together. Would this work or is there a 
better way? Thanks.

                                       sjohns10

Jim Purcell

#1131

sjohns,

I'm a beginner in electronics and I would like to know if there are
any optoisolators out there that would work with audio.Devices in optoisolators are not good for audio as far as I know.
But they do make electronic analog switches. Can't give you a
part # though.

Jim

Borut Wagner

#1164

开云体育

You may use transformers, which are made for telephony?(here in Slovenia we use 300-3400Hz bandwidth?for POTS, I don't know what is in USA, but I think?it isn't much different). Ask in Radio Shack store.

?

Best regards,

?

Borut from Slovenia.

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-----Original Message-----
From: sjohns10@... [mailto:sjohns10@...]
Sent: Thursday, November 01, 2001 3:59 AM
To: Electronics_101@...
Subject: [Electronics_101] optoisolators

I'm a beginner in electronics and I would like to know if there are any optoisolators out there that would work with audio. I want to record my phone conversations (4 seperate lines) but without grounding the actual lines together. Would this work or is there a better way? Thanks.

Doug Hale

#1169

Optical Isolators can be used for analog or audio signals.
You just have to understand the charactoristics of the device you are going to use.

A photodiode/ phototransistor pair functions much like a four terminal transistor - like having a seperate curcuit for the base current - not common with the emitter. All you have to do is bias the photodiode so that the phototransistor  is operating in the center of its linear region.

Doug Hale