[sdiy] Using a phone earpiece as a speaker???

[Scott Gravenhorst]

harrybissell at copper.net wrote:
>You should be able to activate the earpiece...
>its is essentially a speaker. It has two terminals
>you can hook to an amplifier...
>
>The 'old school' mouthpiece is a CARBON
>microphone... it needs to have a DC voltage
>imposed across it (how much ... don;t know)
>and then AC couple the input in to your
>uhhh... input ???

I messed with OLD telephone stuff as a kid.  I used to take a 6 volt battery
connected in series with the carbon mic and the low impedance winding of an
amplifier output transformer.  The high impedance side would directly drive the
earpiece.  I have no idea what the winding/impedance ration of the transformer was.
 YMMV.


>H^) harry
>
>
>>
>>
>>
>>---- Original Message ----
>>From: lief138 at yahoo.com
>>To: synth-diy at dropmix.xs4all.nl
>>Subject: RE: [sdiy] Using a phone earpiece as a speaker???
>>Date: Thu, 11 Jan 2007 10:09:42 -0800 (PST)
>>
>>>Hi Everyone, I wanted to output to a telephone
>>>earpiece, the old kind of phone, you know doubles as a
>>>club....
>>>I found the wires that go to the speaker but its not
>>>happening for me. Does anyone know the secret or where
>>>I might look online?
>>>Also, how about using the talk into part as a mic???
>>>Thanks, Lief
>>>
>>>
>>> 
>>>____________________________________________________________________
>>________________
>>>Need a quick answer? Get one in minutes from people who know.
>>>Ask your question on www.Answers.yahoo.com
>
>
>


-- ScottG

---------------------------------------------------------
-- Scott Gravenhorst
-- Xilinx Spartan-3E Based Music Synthesizers
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/