??? 10/16/07 20:32 Modified: 10/16/07 20:34 Read: times |
#145822 - the key is to remember it\'s a current-loop Responding to: ???'s previous message |
and it often has to reach a LONG way to ring the phone. A lot of this isn't necessary with modern equipment, but the system still has to handle the "old tried-and-true" stuff your parents used.
RE |
Topic | Author | Date |
Telephone line voltages | 01/01/70 00:00 | |
Beware! | 01/01/70 00:00 | |
about that -48 volts ... | 01/01/70 00:00 | |
i did, OUCH | 01/01/70 00:00 | |
the key is to remember it\'s a current-loop | 01/01/70 00:00 | |
The old stuff | 01/01/70 00:00 | |
OK... YOUR grandparents ... MY parents ... | 01/01/70 00:00 | |
Great Stuff ! | 01/01/70 00:00 | |
Pulse dialing | 01/01/70 00:00 | |
Not really surprising. | 01/01/70 00:00 | |
Not necessarily | 01/01/70 00:00 | |
Here, it detects both | 01/01/70 00:00 | |
Pulse Dialling | 01/01/70 00:00 | |
Current Loop | 01/01/70 00:00 | |
Why is that the key?? | 01/01/70 00:00 | |
It's the key to understanding it | 01/01/70 00:00 | |
Sorry, but I cannot see the evidence | 01/01/70 00:00 | |
Your circuit diagram shows it adequately | 01/01/70 00:00 | |
What do you intend to build? | 01/01/70 00:00 | |
What I want to build | 01/01/70 00:00 |