video activated relay

[8cube]

hi all. the attach is a circuit i found on internet, this circui activate a relay when it senses a composite video signal, this allows to use the tuner built into your VCR to turn on and off tVs that are not equipped with a remote. i would like to do this, but i have some confusion,

1. about the tuner, do i need to build the tuner by myself ?

2. according to the circuit diagram , the relay output is connect to "circuit under control",what is that mean? can i directly connect the relay to a socket ? and the TV can straight away plug in to the socket? or do i need to build a "circuit under control?"how does the circuit requirement?

3.in the circuit diagram , that is only DC , but i think the tv need AC , right? so do i need to put a transfomer ? where should i put ? how to decided which kind of transformer to be used?i think normally is 12V or 9V transformer?right?

i know some questions might sound stupid , but i really confuse and .. need help..
thanks for answering

 

[ljcox]

hi all. the attach is a circuit i found on internet, this circui activate a relay when it senses a composite video signal, this allows to use the tuner built into your VCR to turn on and off tVs that are not equipped with a remote. i would like to do this, but i have some confusion,

1. about the tuner, do i need to build the tuner by myself ?

You would use the AV output from the VCR. ie. connect the video output of the VCR to the input to the circuit.

2. according to the circuit diagram , the relay output is connect to "circuit under control",what is that mean? can i directly connect the relay to a socket ? and the TV can straight away plug in to the socket? or do i need to build a "circuit under control?"how does the circuit requirement?

The relay contacts would be connected in series with the mains supply to the TV. But be sure to use a ralay that can handle the voltage and current.

3.in the circuit diagram , that is only DC , but i think the tv need AC , right? so do i need to put a transfomer ? where should i put ? how to decided which kind of transformer to be used?i think normally is 12V or 9V transformer?right?

To obtain 9 Volt DC you would use a 6 Volt AC supply from a transformer and full wave rectify it and smooth it with an electrolytic capacitor - about 2200 uF would suffice.

Len