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Dave Moll · 16th Feb 2021, 11:03 am

The dolls' eyes (for the extensions) are operated from the 12V DC by detecting a loop when the extension goes off-hook (or goes back on-hook when the line is selected). The drop-down indicators for the exchange lines are operated by the incoming ringing current.

When a doll's eye operates it closes a contact to operate an internal buzzer.

16th Feb 2021, 11:03 am	#2
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: CB935 switchboard queries The dolls' eyes (for the extensions) are operated from the 12V DC by detecting a loop when the extension goes off-hook (or goes back on-hook when the line is selected). The drop-down indicators for the exchange lines are operated by the incoming ringing current. When a doll's eye operates it closes a contact to operate an internal buzzer. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)