| T O P I C R E V I E W |
| mahdi |
Posted - Jan 03 2008 : 5:17:52 PM
i am trying to design a tone genrator circuit for busy tone 400Hz . i need eny design . can you help me in this case ? |
| 4 L A T E S T R E P L I E S (Newest First) |
| mahdi |
Posted - Jan 04 2008 : 3:52:23 PM
I love your country very much specially british culombia university thank you for informations . i am electronic enginiering and intrest in telephone line . dtmf signal , intercomunication system , telephone secretary , answering machine , diaier , autoredialer, caller ID and etc. dont you have eny question in this topic? |
| audioguru |
Posted - Jan 04 2008 : 2:35:42 PM
In Canada the ringing signal is a 20Hz sine-wave at 90VAC. Local calls have a cadence of 2 seconds on then 4 seconds off. Long distance calls have 2 rings in one second then a 3 seconds pause.
At rest, the DC voltage on the telephone line is 51V. |
| mahdi |
Posted - Jan 04 2008 : 04:22:04 AM
hi dear frind . what is the ringing signal voltage in your country?
can you get me some informations abuot telephone line in canada? |
| audioguru |
Posted - Jan 03 2008 : 6:24:10 PM
Here in North America a telephone busy signal is two tones at 480Hz and 620Hz.
Just make a 400Hz sine-wave oscillator for your country. |
