Bit off help if anyone can

[aitch100]

I've got a drop down monitor in the van with hdmi / av / USB it has a built in sleep timer that turns it off I also have a separate dvbt tuner that I want to turn off with the timer can I use a 5v relay connected to the +/- of the USB without doing any damage to the monitor ( power spikes ) etc
thanks

[Tough]

You want power a dvbt tuner by usb of monitor right? well it could work

[aitch100]

The tuner is 12v to be powered by the van batteryI need the relay to switch it on and off by using the 5 v from the usb to power the relay coil so when the monitor is on the relay would be powered and switch on the 12v to the tuner (if that makes any sense)

[Meat-Head]

Yes makes perfect sense. Look on ebay, might be a better option, but cant see
why that wont work, in theory, or just install seperate switch with a DK thanks button, or junk the lot and post on dk more