| ??? 10/16/07 10:42 Read: times |
#145801 - Telephone line voltages |
Is there any defined standard for DC and AC voltages which are common in telephone communications? I've found ITU standards for signaling but not line voltages.what are acceptable electrical characteristics of a standard telephone line?
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| 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 |