I have to electronic devices that will share 1 9v power supply. Each device will have its own power button. What I'm trying to figure out is what type of relay I would need so that when device 1 gets turned on device 2s power button will become disabled. When device 2 is powered on device 1s power button gets disabled. So that both of them cannot be turned on at the same time. Space inside the enclosure is limited. So this relay or circuit board will need to be as