Re: German to UK phone wiring

["Keith Doxey" <keith.doxey@xxxxxxx>]

Hi Tim,

In the days of the old strowger exchanges, the output of the ringing
machine
was 17Hz sinewave but all the power units for the old PABX's gave out 25Hz
sine wave. For phones with a "proper" bell the frequency must be
kept quite
low or the mechanical bits of the bell will not work properly.

All modern phones will work with almost anything (including DC applied
across 3 & 5) as the ringing sound is actually produced by a chip. The
AC
ringing passes through the capacitor into the ringing circuit where it is
rectified to DC to drive the chip.

Try it out and see how you get on. You wont do any damage so long as the
PBX
is designed for 2 wire analogue phones.

Keith Doxey
http://www.btinternet.com/~krazy.keith
Krazy Keith's World of DIY HomeAutomation


> -----Original Message-----
> From: Timothy Morris [mailto:timmorris@xxxxxxx]
> Sent: 08 September 1999 18:28
> To: ukha_d@xxxxxxx
> Subject: [ukha_d] Re: German to UK phone wiring
>
>
> The four wires are designed for connection of ordinary telephones,
modems,
> etc. Perhaps one of the lines is also earth? I've done some more
checking
> and the ring signal generated is a 25Hz square wave. Do you know what
UK
> phones are expecting?
>
> Tim.
>
> > -----Original Message-----
> > From: Keith Doxey [mailto:keith.doxey@xxxxxxx]
> > Sent: 08 September 1999 15:22
> > To: 'ukha_d@xxxxxxx'
> > Subject: [ukha_d] Re: German to UK phone wiring
> >
> >
> > Hi Tim,
> >
> > The ringing is not GENERATED by the master socket.
> > It is already present on the line assuming it is intended for a
normal
> > analogue telephone. The master socket merely EXTRACTS the ringing
and
> > places it on the third wire.
> >
> > Line connects to 2 & 5
> > ringing is extracted fron 2 by a 1.8uF capacitor and placed onto
3.
> > the ringer in the phone is connected to 3 & 5
> > the speech circuit is connected to 2 & 5
> > recall earth if required is connected to 4
> >
> > If you have 4 terminals on your PBX it may be intended to connect
to
> > dedcated key systemphones.
> > Typically one pair is for speech and the other for data although
> > there are
> > digital systems that only use one pair (Norstar) or seperate
pairs for
> > transmit and receive data (Octara)
> >
> > Without exact details on your system I cant advise exactly, but
> > if you have
> > already tried to connect a phone to the speech pair and had dial
> > tone, you
> > will not do any damage by connecting  a master socket, or
> > secondary socket
> > with 1.8uF capacitor connected between 2&3 to see if it
rings.
> >
> > for more information look at my website in the telephones
section.
> > http://www.btinternet.com/~krazy.keith/telephones/pots.html
> >
> > Keith Doxey
> > http://www.btinternet.com/~krazy.keith
> > Krazy Keith's World of DIY Home Automation
> >
> >
>
>
>
------------------------------------------------------------------------
> MyPoints-Free Rewards When You're Online.
> Start with up to 150 Points for joining!
> http://clickhere.egroups.com/click/805
>
>
> eGroups.com home: http://www.egroups.com/group/ukha_d
> http://www.egroups.com -
Simplifying group communications
>
>
>
>
>


------------------------------------------------------------------------
MyPoints-Free Rewards When You're Online.
Start with up to 150 Points for joining!
http://clickhere.egroups.com/click/805


eGroups.com home: http://www.egroups.com/group/ukha_d
http://www.egroups.com - Simplifying
group communications