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Line monitor circuit diagrams
December 2, 2010
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... [more]
October 25, 2010
This nifty little circuit lets you record your phone conversations automatically. The device connects to the phone line, your tape recorder's microphone input, and the recorder's remote control jack. It senses the voltage in the... [more]
October 14, 2010
If you feel that somebody is tampering with your telephone line you might find this little circuit useful. It detects if there is another telephone connected to the line, if there is a short or... [more]
April 25, 2010
It is a relatively simple circuit, with which we can have optical and sound clue, when we have telephone ring in the line of telephone. The calls in the line, are changed in pulses of... [more]
April 25, 2010
If we have a lot of parallel telephones on a telephone line, we needed a unit that will have the possibility of showing if somebody of the telephone has raised the earphone. [more]
April 25, 2010
A very simple circuit, that will find application in the case where you have a lot of telephones installed on a telephone line and would want to know if somebody of them is open. Thus... [more]
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