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'Can a speaker be Input Devices'
2003\06\02@122418 by Tal

Yes. When I was a kid, I used to built intercom circuits that used the
speaker for both input and output. The PTT switch used to switch the
speaker between the amplifier input and output.


> {Original Message removed}

2003\06\02@165808 by ?q?Debbie=20Hynes?=

Sure, but impedance matching is the problem. U need to amplify it but since the
speaker's Z is 8 ohm, u need to use an 8 ohm/1K audio transformer to step up
the sig & impedance if feeding into a common emitter amplifier.
If u don't want to use a transformer, u can put the spkr in the emitter leg
(low Z) of a common base ampifier and match Z's & boost o/p sig that way.


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