I have a little project to mount my garage door opener in my car, and power it from the car's 12V supply. The door opener is powered by a couple of coin batteries in series, for a total of 6V. I plan to run a couple of wires in parallel to the pushbutton the PCB to another button on the dash somewhere.
Also, following some comments on here, I'm a bit leary about a cheap AliExpress buck converter, which might fail and put 12V across my only door opener and fry it. But given the (I assume) low current and intermittent use, power efficiency isn't a big deal. I'm assuming that the door opener only uses current when the button is actually pressed. Any idea about that?
So, would a LM7806 linear converter be OK? Do they fail safe? I prefer a fixed voltage anyway.