🚀 go-pugleaf

I looking for a circuit design toperform the following telephone function:

Security systems which automatically dial out to report a disturbance
use some sort of telephone line device which automatically "captures"
the telephone line.  At the moment the Security System itself goes
Off-Hook 
to prepare to dial out, the line capture circuit automatically senses Off
Hook 
and disconnects any extension telephones that may be off-hook.  Then the 
circuit regains a dial-tone by switching the telco line to On Hook for a
second 
and then goes back Off-hook to allow the security system to dial out.

Any ideas?  Thanks, 

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Ed Neubauer          
Plano Tx
Email: [uunet!]iex!neubauer or neubauer@iex.com
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