🚀 go-pugleaf

In article <1315@minnow.sp.unisys.com> ron@minnow.UUCP (Ron Burns) writes:
>...  I want 
>to be able to sense whether the phone is off the hook at another extension
>so as not to slam an earful of phone dialling tones into someone's ear.
> ...
>the requirements seem simple:
>	1)  TTL compatible output indicating phone off hook at extension
>		or local phone jack.
>	2)  No interference with normal phone operation.
>	3)  (optional) Phone line powered to allow use at other extension.
>
>Can someone out there help me with this??  Telephone circuits are just a  
>mystery to me, even though this seems fairly simple.

I recently bought an amazingly cheap gizmo for this sort of thing.
I've never seen it for sale anywhere else.  It is in the Fordham-Scope
catalog.  (I don't have the number/address here at work.  NY area,
with an 800 number, I think.)

It's a model MS-2 "Message Stopper", price $7.95 (I think, maybe 8.95).
It looks like a two-for-one modular jack.  One nose that goes into
the wall socket, two sockets for two cords.  There are two LEDs for
activity on the two sockets.

One socket is just a copy of the input.  The other socket gets
cut off if anyone else is using the line.  So it can be used for
answering machines that don't automatically drop off when the
line gets picked up elsewhere.  Or for the Watson board, which
doesn't drop off either.  You could do what you want by having
the PC try to make the call, but fail, because it isn't connected
to the line when someone's on it.   No TTL output, sorry.  Meets
your items 2 and 3, though.  Maybe you could rig a sensor on
the LEDs if you really need it, but that would need isolation and
all that.  Maybe a photocell looking at the LED.

Note:  When I first saw the ad, I assumed it just had a relay in it
that sensed current through one jack and cut off the other.  Not so!
It really does sense voltage, so it cuts off when any other phone
on the line is off-hook.

So why doesn't anyone else sell this little gem?

>
>Thanks a lot!!
>-Ron
>-- 
>Ron Burns              
>Unisys Corporation  UUCP: ...!amdahl!ems!minnow!ron   
>Phone:(612)635-6927 CSNET: ron@minnow.SP.Unisys.Com

/Rcc
clements@bbn.com