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Old 15th Aug 2018, 10:13 pm   #8
OscarFoxtrot
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Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 805
Default Re: Payphone 500 / 600 handsets

Quote:
Originally Posted by Dave Moll View Post
The only other reason for needing a DC voltage there that I can think of is to energise a field coil if a receiver uses one of these instead of a permanent magnet.
Interesting idea.

Inside the capsule and with the induction loop removed there are two coils either side of a small magnet on the armature. Bypassing the induction loop gives a loud click on one polarity and no click on the other polarity, but I'll experiment further tomorrow.

Thanks.
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