We can say that now in Russia there is the flourishing DVD technology. Very available sells DVD players and recorders, home theaters, and more. But all this should work together with the TV.
Even if you decide to make a "stereo system" combining multi-format DVD player with a powerful improvised USC with speakers, you still have the TV on so on its screen can select the tracks, view videos, and other than now accompanied by MP-3 recordings made on DVD.
My DVD-music center" was going gradually. First, to the TV set "Vityaz-TS-6024-1" was bought multiformat DVD player "UNITED-DVD-7064" that can play not only DVD movies, but just as the music MP-3, CD and etc. Output stereo sound with adjustable volume and equalizer (with remote DVD player). Of course, the sound quality staffing. AC TV (two narrow dynamics along the edges of the kinescope) left much to be desired.
Therefore, according to one publication in the journal was additionally collected stereo unch at IC for automotive vehicles powered by conventional transformer source. Now the task is how to manage this VLF to turn on and off. simultaneously with TV.
As a result of reflection and experimentation the scheme shown in the figure. This is dependent switch car relay type 98.3777-10, sold in any auto shop as a "relay 4-pin to VAZ, at a price of 40-50 rubles Relay in plastic housing, with a coil 12 In impedance of 70 Ohms. Of course, designed for switching low-voltage circuits, but its counterpart SCB-1-M-1240, judging according to the reference data from the Internet, can run on a voltage of 220 V AC current up to 5 A. So the relay was tested on switching 220 V and found to fit me personally.
The circuit works. TV set "Vityaz-TS-6024-1" in the on state takes the power of 60 watt. In the state of Stand-By power less than 1 watt. So consumed current and the mode will be about 0..3 And, as in "Stand-By" about 5 mA. Winding the relay has a resistance of 70 Ohms, i.e. at rated voltage it takes the current about 0.17 A, which corresponds to the power of the TV is 37 watts.
Thus, if through the relay coil to connect the TV in "Stand-By", relay does not switch, but when it's winding will burn easily. The diagram in VD1 and VD2 selects one of the half-wave voltage supply TV a voltage of about 14 V. This pulsating voltage is rectified by the diode VD3 and smoothed by the capacitor C1, and then is supplied to the relay coil.
If the TV is off no current at all, and no voltage on the relay coil. If the TV is on in the mode "Stand-By", i.e., turned off with the remote control, the current power relay coil will be very low (about 5 mA), and the relay is not switches, as he had 170 mA. When the TV is switched on in the operating mode the voltage and current increases. The relay is activated and turns on the power to the ULF. Powerful Zener diode VD2 protects the relay coil from damage by limiting the voltage and removing the excess current.
Now a few words about the use of this switch.
If the power of the TV or other "main consumer" below 40 watts - look another relay, the winding of which consumes less current. If power consumption "main consumer" is much higher, for example, the system unit of a personal computer, it is necessary in parallel with the Zener diode VD2 to include one or several Zener diodes, taking 150 W maximum output for each diode.
That is, for example, at a power of 250 watts, you need two Zener in parallel, and when power 400 watts - three in parallel.
All located in a building with three sockets for external wiring. One socket is removed, and this part contains the scheme of volume mounting. Turned out to be an extension cord with two sockets: "Home" and "Dependent".
Author: A. A. Mezentsev