Talk:Ringing (telephony)

what the heck exactly is this article anyway. I found it by searching "20 hertz". It doesn't seem to make any sense. Is this saying that what triggers your phone to ring is a 20 hertz control tone, because the ring itself is certainly not. Daniel Christensen (talk) 20:14, 15 April 2010 (UTC)

The 20-Hz signal is what is actually applied to the telephone line to signal an incoming call, and it is turned on and off to generate the proper ringing cadence (e.g. 0.4 sec. on, 0.2 off, 0.4 on, 2.0 off for the British double-ring; 2 secs. on, 4 secs. off in North America, 1 sec. on and 3 or 4 secs. off in much of Europe, etc.).

With a traditional telephone set, this ringing current operates the ringer directly to cause the armature to vibrate and hit the bell gongs. With modern electronic ringers, it is used to power the oscillator which generates the electronic ring, or in some cases it does act as just a signal and the power for the circuitry which actually generates the audible "chirp" or other sound is derived from elsewhere.

And just to finish, although 20 Hz is common, other different ringing frequencies can be found, e.g. in some countries 16 or 17 Hz is the more usual standard. At one time, especially in North America, different ringing frequencies between about 16 & 60 Hz were sometimes used on party lines to distinguish between calls for each party, the ringers in the phones being tuned to operate only on the appropriate frequency. 87.114.88.41 (talk) 14:41, 29 May 2012 (UTC)