Hello all...my first time posting. I need to create a circuit that selects between 2 dc power sources (PS A and PS B) with a push button. It is ok if cause an slight interruption in power during the switching process. I can fire the relay to switch power sources well enough, but as soon as I press the button to switch, the relay dies and it defaults back to the PS A. (assuming PS A is where I am starting from.) I know it has something to do with keeping the relay coil energized during the switchover. I also need to be able to switch from PS B to PS A again after that, with the same button. I am stumped. any ideas? thanks in advance.