| Author | Views | Views Today | Rank | Comments |
| 36,349 | 35 |   |
14 |
| Author | Views | Views Today | Rank | Comments |
| 36,349 | 35 | |
14 |
| Have you ever been using the modem or fax and someone else picks up the phone, breaking the connection? Well, this simple circuit should put an end to that. It signals that the phone is in use by lighting a red LED. When the phone is not in use, a green LED is lit. It needs no external power and can be connected anywhere on the phone line, even mounted inside the phone. |
Schematic |
Parts |
|
Notes |
Related Circuits |
Comments |
| i want ot know the complete description of parts and working of Phone Busy Indicator.also i want assurance that when implemented on pcb it works well..tells us about another ic no of npn taransistor because the spicpied one is not available if phone busy indicator work on them then tell us....Hi! im jake. can u help me with my project. How can i determine if i call then the receiver is answer the call? waitng for reply..... WANT TO KNOW HOW THIS CIRCUIT IS WORKING IN DETAIL ,ITS APPLICATION...plz do mail me all decriptions n details widin two days to mine mail id | ||
| i want ot know the complete description of parts and working of Phone Busy Indicator.also i want assurance that when implemented on pcb it works well. | ||
| tells us about another ic no of npn taransistor because the spicpied one is not available if phone busy indicator work on them then tell us. | ||
| think you | ||
| I assembled this circuit and it works really great, now I can tell when somebody has the phone extension in use. Building it was really cheap and easy. Other circuits i saw were more complex and required external power. Thanks to the author for that nice piece of work | ||
| i need a full description in this..thanks.. | ||
| Hi! im jake. can u help me with my project. How can i determine if i call then the receiver is answer the call? waitng for reply. | ||
| i want to know about the working of phone busy indicator in detail and it's applications. | ||
| I WANT TO KNOW HOW THIS CIRCUIT IS WORKING IN DETAIL ,ITS APPLICATION........PLEASE VERY FAST IN 5 HOURS | ||
| Hello you, I just looked your phone busy indicator cct and I would like to know how can I add a PIC 12C508A to fit within ? I only want to make my PIC 12C508A program started if line is not in use. a) Should I connect one of the PIC pin instead of led 1 ? b) I don't need led2 (should I only remove the led? should R2/3/4/5 values be changed ? Tks for answering the newbies that I'am : ) Tks/Carl | ||
| The last 10 comments are currently shown. Show All Comments. |
If you would like to leave a comment, you can do so using the form below. Comments can be things like suggestions, successes or failures, improvements, similar circuits, error reports, an answer to a previous commenter's question, or anything in between. However if you would like to ask a question it is suggested that you use the forum instead. The forum provides a more robust environment for discussion.
Important: If you post a technical question here, there is no guarantee it will be answered. All technical questions should be posted to the forum. The owner of this site generally does not answer questions in comments.
All comments are subject to approval before they are displayed here, so your comment will not appear immediately. This is done mainly to prevent spam and other abuse. If you wish to remain anonymous, simply enter "anonymous" for your name and/or email.