How to design an Automatic light switch when video signal detected

Thread Starter


Joined Nov 29, 2017
Hi, kinda new here so apologies if im on the wrong forum. It will become quite apparent that I'm a complete newb at this but keen to learn! Just looking for some pointers really as not sure where to start , hoping someone will take pity and get me going

What I want to achieve is a switch that will control a small led light which will turn it on when a video signal is detected

Is this possible a. Without spending a fortune on components and b. For multiple units.

What I'm wanting is a display cabinet for some vintage games consoles where the cabinet light turns on automatically when a device is powered on. (One for each)

I'm guessing that detecting the video output is one way of doing it but no idea how this might be done!

Google isn't my friend on this so far ... can anyone help point me towards some info that will help or maybe some pointers?

Would really appreciate any help!


Joined Aug 1, 2013
Detecting something non-zero in a video signal wire certainly is possible, but is there a reason why you can't just detect when the unit is turned on? A neon light connected to the AC power *after* the on/off switch is a very old idea. Adapting it to use an LED is fairly simple.