TH514C3 - Anti-theft tape recorder And wiretapping on the phone - Google Patents

Abstract

It is a simple and uncomplicated circuit design to increase the voltage drop across the line. The telephone line has a voltage greater than 30 volts (while picking up the handset) to prevent any other tapes or wiretapping devices using the electromagnetic force sensing principle in the telephone line to Work automatically And it creates noise in the telephone line all the time when the phone is not used to trick the recording Or other types of wiretapping devices that control work with various sound signals to work all the time (To empty the tape cassette first). All such operations must Does not affect the normal use of the company And the sound quality must not deteriorate Incidentally, the owner of the device The phone can install this device by itself. Which can be connected reversed on both sides And does not require any external electricity or batteries

Claims (2)

1. Anti-burglary phone tape recorder It consists of a booster circuit in the line. Phone in use with zener diode or IC number LM431 and use CONDENSOR to cross the zener diode or IC number LM431 to avoid signal degradation. 2.Voice-activated telephone (VOX) anti-theft device using an astable multivibrator noise-generating circuit And use Zener diodes as an automatic switch to Control circuit operation By relying on the power from the telephone line