| Author | Views | Views Today | Rank | Comments |
| 32,908 | 48 |   |
22 |
| Author | Views | Views Today | Rank | Comments |
| 32,908 | 48 | |
22 |
| A while ago I got an email asking for the schematic of a circuit to detect cut phone lines. It didn't take me long to find this circuit in Electronics Now. When the circuit detects that a phone line has been cut, it activates a MOSFET which can be used to drive a relay, motor, etc. It can also be connected to a security system. |
Schematic |
Parts |
|
Notes |
Related Circuits |
Comments |
| is this applicable in wider range of detecting the cut of a wire? | ||
| Can I find a circuit already built? | ||
| its a good circuit but i want to find like that circuits when talking will start and circuits cut the line which are predefine by us for exaple after 5 mins,10 mins and etc. if u have a like this circuits please send it my email address on urgent basis email address is | ||
| if i used the wirless phone it could be work and tell me how i connected with it and if you give me the more and more knowledge plz help me any one knows it thanks | ||
| thank you, very good but sir could you please provides more information about this. | ||
| Oops! I missed the the diode on the input. I guess it does have ring protection after all. Sorry! | ||
| As another poster said "Remove the reference to GND"!! It's a very bad thing to do, and will most certainly set off alarms it Ma Bell! I also agree that most of the resistor values are excessively high. & the input has no protection from the AC Ring voltage! | ||
| soooo good circuit but we need more information about it like data sheet of transistors | ||
| I just looked at the cut phone line detector schematic. I need a circuit that will detect a break in in continuity of a single wire that I thread physically through a display of Christmas wire forms that if cut will in turn activate a 110VAC circuit to a siren/whaler, lights etc. PS. I have a basic knowledge of electricity/electronics and would prefer to have someone build me such a circuit. It looks like a fairly basic relay circuit, but is probably more in depth. Thanks | ||
| Dear all My question is how could we use this circuit, i.e. what is the function of this circuit. another question is I am looking for circuit its function to find lost telephone wire | ||
| 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.