Home Projects Telephone Related Telephone line monitor

 

 

Telephone line monitor


Telephone Recorder

 

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 phone line and begins recording when the line drops to 5 volts or less.

 

Schematic


This is the schematic of the Telephone Recorder

Parts

Part

Total Qty.

Description

Substitutions

R1

1

270K 1/4 W Resistor

R2

1

1.5K 1/4 W Resistor

R3

1

68K 1/4 W Resistor

R4

1

33K 1/4 W Resistor

C1

1

0.22uF 150 Volt Capacitor

Q1, Q2

2

2N4954 NPN Transistor

D1

1

1N645 Diode

MISC

1

Wire, Plugs To Match Jacks On Recorder, Board, Phone Plug

Notes

1. The circuit can be placed anywhere on the phone line, even inside a phone.

2. Some countries or states require you to notify anyone you are talking to that the conversation is being recorded. Most recoders do this with a beep-beep. Also, you may have to get permission from the phone company before you connect anything to their lines.

 

 
 

 

Search Site | Support us | Advertising | Profile | Books | Gadgets | Add your link here | Contact Us


IQ Technologies @ copy right 2008

Powered by Wild Host   Site Design By : FRIEND