Can anyone tell me what the spec is for the old style ringing tone? Please note, I am not looking for ringback tone spec but the spec for the tone that rings a telephone set. I know, in North America, it is something like 2 sec on and 4 sec off. But I am looking for frequcencies, modulations, and etc. or, say, how it is generated. Thanks a lot. Li
Ringing tone spec help!!
Started by ●September 23, 2004
Reply by ●September 23, 20042004-09-23
Hello Li, Actually what rings the phone is not a tone per se., but rather a low frequency high voltage AC signal. IIRC it is in the order of 25-30Hz and something like 90-105 volts. The frequency actually matches a mechanical resonance in the bell itself. Bell was able to do selective ring by changing the ringing frequency. Sorry I can't remember more - it has been several decades since I worked with that. Clay "L. Hao" <lhao@vertical.com> wrote in message news:mAI4d.319$BG5.49958@news.uswest.net...> Can anyone tell me what the spec is for the old style ringing tone? Please > note, I am not looking for ringback tone spec but the spec for the tonethat> rings a telephone set. > > I know, in North America, it is something like 2 sec on and 4 sec off. ButI> am looking for frequcencies, modulations, and etc. or, say, how it is > generated. > > Thanks a lot. > > Li > >
Reply by ●September 23, 20042004-09-23
L. Hao wrote:> Can anyone tell me what the spec is for the old style ringing tone? Please > note, I am not looking for ringback tone spec but the spec for the tone that > rings a telephone set. > > I know, in North America, it is something like 2 sec on and 4 sec off. But I > am looking for frequcencies, modulations, and etc. or, say, how it is > generated. > > Thanks a lot. > > LiI don't know the spec, but 20 Hz AC at 80 V will do it. The frequency can't be very tight, because a hand-cranked alternator will do it (it was standard once). Western Electric used to supply line-operated ring generators for PBXs (the hand crank was there for backup) that through magnetic nonlinear iron cores in tuned circuits produced the "1/3 harmonic" of the power line. Jerry -- ... they proceeded on the sound principle that the magnitude of a lie always contains a certain factor of credibility, ... and that therefor ... they more easily fall victim to a big lie than to a little one ... A. H. �����������������������������������������������������������������������
Reply by ●September 24, 20042004-09-24
Jerry Avins wrote:> L. Hao wrote: > >> Can anyone tell me what the spec is for the old style ringing tone? >> Please >> note, I am not looking for ringback tone spec but the spec for the >> tone that >> rings a telephone set. >> >> I know, in North America, it is something like 2 sec on and 4 sec >> off. But I >> am looking for frequcencies, modulations, and etc. or, say, how it is >> generated. >> >> Thanks a lot. >> >> Li > > > I don't know the spec, but 20 Hz AC at 80 V will do it. The frequency > can't be very tight, because a hand-cranked alternator will do it (it > was standard once). Western Electric used to supply line-operated ring > generators for PBXs (the hand crank was there for backup) that through > magnetic nonlinear iron cores in tuned circuits produced the "1/3 > harmonic" of the power line. > > JerryIt depends where you are, and the how old the equipment. The common frequencies ate 16.67Hz, 20Hz and 25Hz. There seems to be some 50Hz around the world, too. These days the frequency is generally pretty accurate, but in older systems it was all over the place. The voltage is typically 90-110V RMS, and is usually added to the standing -48VDC on the line. The peak negative excursion is, therefore, quite large. That point catches out some designers of quench circuits, which pop their tiny surface mount resistors after a while :-) Regards, Steve
Reply by ●September 24, 20042004-09-24
Thanks Clay and Jerry for the information. Well, if I want to reprodue this sound through software, is there an algorithm out there I can look for? Again, thanks a lot! Li "Jerry Avins" <jya@ieee.org> wrote in message news:41536fc1$0$4026$61fed72c@news.rcn.com...> L. Hao wrote: > > > Can anyone tell me what the spec is for the old style ringing tone?Please> > note, I am not looking for ringback tone spec but the spec for the tonethat> > rings a telephone set. > > > > I know, in North America, it is something like 2 sec on and 4 sec off.But I> > am looking for frequcencies, modulations, and etc. or, say, how it is > > generated. > > > > Thanks a lot. > > > > Li > > I don't know the spec, but 20 Hz AC at 80 V will do it. The frequency > can't be very tight, because a hand-cranked alternator will do it (it > was standard once). Western Electric used to supply line-operated ring > generators for PBXs (the hand crank was there for backup) that through > magnetic nonlinear iron cores in tuned circuits produced the "1/3 > harmonic" of the power line. > > Jerry > -- > ... they proceeded on the sound principle that the magnitude of a lie > always contains a certain factor of credibility, ... and that therefor > ... they more easily fall victim to a big lie than to a little one ... > A. H. > ����������������������������������������������������������������������� > >
Reply by ●September 24, 20042004-09-24
L. Hao wrote:> Thanks Clay and Jerry for the information. Well, if I want to reprodue this > sound through software, is there an algorithm out there I can look for? > > Again, thanks a lot! > > LiIt's not just a sound. I can usually grab hold of an idle telephone line without noticing. (You certainly can when the line is in use.) You will certainly notice if you happen to be touching the line when it rings! The ringing generator will readily light the small bulb in a night light. I wrote that 80 V would do. 100 V is more typical. The short answer is that you must be prepared to deliver about 20 watts with a circuit can withstand a short. Jerry -- ... they proceeded on the sound principle that the magnitude of a lie always contains a certain factor of credibility, ... and that therefor ... they more easily fall victim to a big lie than to a little one ... A. H. �����������������������������������������������������������������������
Reply by ●September 24, 20042004-09-24
Jerry Avins <jya@ieee.org> writes:> L. Hao wrote: > > > Thanks Clay and Jerry for the information. Well, if I want to reprodue this > > sound through software, is there an algorithm out there I can look for? > > Again, thanks a lot! > > > Li > > > It's not just a sound. I can usually grab hold of an idle telephone > line without noticing. (You certainly can when the line is in use.) You > will certainly notice if you happen to be touching the line when it > rings! The ringing generator will readily light the small bulb in a > night light. I wrote that 80 V would do. 100 V is more typical.I can still remember when I was a boy of about 5 watching my father wire up a new phone jack in one of the rooms. All of a sudden he *jumped* while he had the wires in his hand! Incoming call. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA randy.yates@sonyericsson.com, 919-472-1124
Reply by ●September 24, 20042004-09-24
Randy Yates wrote:> Jerry Avins <jya@ieee.org> writes: > > >>L. Hao wrote: >> >> >>>Thanks Clay and Jerry for the information. Well, if I want to reprodue this >>>sound through software, is there an algorithm out there I can look for? >>>Again, thanks a lot! >> >>>Li >> >> >>It's not just a sound. I can usually grab hold of an idle telephone >>line without noticing. (You certainly can when the line is in use.) You >>will certainly notice if you happen to be touching the line when it >>rings! The ringing generator will readily light the small bulb in a >>night light. I wrote that 80 V would do. 100 V is more typical. > > > I can still remember when I was a boy of about 5 watching my father > wire up a new phone jack in one of the rooms. All of a sudden he > *jumped* while he had the wires in his hand! Incoming call.Been there. Jumped too! jerry -- ... they proceeded on the sound principle that the magnitude of a lie always contains a certain factor of credibility, ... and that therefor ... they more easily fall victim to a big lie than to a little one ... A. H. �����������������������������������������������������������������������
Reply by ●September 24, 20042004-09-24
L. Hao wrote:> Thanks Clay and Jerry for the information. Well, if I want to reprodue this > sound through software, is there an algorithm out there I can look for? > > Again, thanks a lot! > > Li >-- snip -->Are you trying to replicate the ring sound of a telephone with mechanical bells, or the sound you'd get if you connected the line to a loudspeaker? The easiest thing to do may be to get a high-quality recording of such a phone and play it back -- but you'll need a good audio system to reproduce the high-frequency pulse when the clapper strikes the bell. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Reply by ●September 26, 20042004-09-26
Jerry Avins wrote: (snip)> I don't know the spec, but 20 Hz AC at 80 V will do it. The frequency > can't be very tight, because a hand-cranked alternator will do it (it > was standard once). Western Electric used to supply line-operated ring > generators for PBXs (the hand crank was there for backup) that through > magnetic nonlinear iron cores in tuned circuits produced the "1/3 > harmonic" of the power line.If I understand the system once used, though I never saw one, there once were "party lines" where more than one house was connected to the same phone line. The ringer circuits then used resonant circuits to separate different ring signals for different phones, though only one could talk at time. (I believe the filter was not inside the phone, but somewhere else.) -- glen
