The automatical switch for TV aural transmitter

Published:2012/8/21 1:43:00 Author:Ecco | Keyword: automatical switch , TV , aural transmitter | From:SeekIC

The principle: when the TV is turned on, it will generate a strong electromagnetic field around TV, the electromagnetic field is mainly generated by the line scanning system of the television kinescope. TV line scanning frequency is 15.625kHz. So compared to the AC mains, the frequency is higher. As long as detecting the electromagnetic field, it will complete the task by turning on the power switch of broadcast system. In order to make the circuit simple without higher cost, electronic switch for the circuit is served by FET VT. Because the required driving power FET is minimal, it does not need drive current almost. The magnet coil L absorbes to open the TV, then the energy of the electromagnetic field will be generated around the TV.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Basic_Circuit/The_automatical_switch_for_TV_aural_transmitter.html

Print this Page | Comments | Reading(3)