Video signal detection

cxq742536574

Video signal detection [Copy link]

I want to use the CVBS video signal line to determine whether there is a camera without affecting the signal on the signal line. What solutions can be used? After the video signal passes through the circuit, the high and low levels can be directly output.

cxq742536574

Can this circuit detect video signals?

chunyang

If the video signal is analog, a DC level output circuit can be added to the camera, and the video signal is separated by capacitor coupling, but this method will reduce the anti-interference ability of the video signal, and if the DC level fluctuates, it will interfere with the video signal. This method is not suitable for long cables. Another way is to split the video signal, then amplify and integrate it, so that it can be judged without affecting the camera and cable.

chunyang

cxq742536574 posted on 2022-2-17 17:59 Can this circuit detect the presence of a video signal?

This circuit is useless unless the input signal is strong enough, including sufficient voltage and current, and it can only operate once within a certain period of time. Why don't you first talk about why you designed the circuit this way?

cxq742536574

chunyang posted on 2022-2-17 20:31 This circuit is useless unless the input signal is strong enough, including voltage and current, and it can only operate once within a certain period of time. You might as well talk about it first...

To switch different cameras, the premise is to know how many cameras exist, and there are only video signals, so we can only determine whether a camera exists by detecting the video signal.

chunyang

cxq742536574 posted on 2022-2-18 15:12 To switch different cameras, the premise is to know how many cameras exist, and there are only video signals, so it can only be detected by detecting video signals...

You cannot connect multiple cameras in parallel on the same line. If you want to switch, you can only do it according to the preset channels, which cannot achieve the function you want. Moreover, your circuit has nothing to do with this. You should first figure out what the demand is.