How can I connect this circuit to power?

[laurenhrv]

I am trying to build an escape room puzzle, where someone holds a key fob up to a sensor and a maglock opens, and I went online to buy something that I assumed was ready-in-box but instead they sent me the photo attached which I'm 99% sure was originally a car immobilizer and is now being used as a sensor with attached output. My questions is - how do I connect this to power? I have some knowledge in electrical engineering, enough to recognize most of the parts here but this is the one mystery I cannot solve. The whole thing I assume takes 12V power. Does anyone have an insight into how to give it power, or even how to set it up in general?
In photo: circuit board in the center, sensor (large, black) just off center right, attached chip up top/middle is output (for maglock), coiling wires off the right side is just a singular LED light, and included fobs are top-right. The rest is a mystery.

 

[kellys_eye]

The red and black wires that are part-stripped are prepared for the 12V supply source.



Those two wires (red/black) seem to go to the device shown above which will be a 5V regulator.

Use an in-line fuse in the supply feed - a 3A fuse should do.

 

[laurenhrv]

Thank you! That makes perfect sense now that I think about it. That being said, I think I may have shorted the whole thing. I connected it to a 9V battery and it worked, then I tried connecting it to a 12V cord and to a 13.5 V cord (black wire inside, red wire around the outside), neither worked and then it never worked again. In general is there any way to figure out how much voltage is supposed to be going through or why it just broke suddenly? Does the 5V regulator indicate anything and is it possible that it blew? The output is labelled as 12V if that helps. I apologize for my seemingly complete lack of all knowledge but I appreciate any advice.

 

[kellys_eye]

I tried connecting it to a 12V cord and to a 13.5 V cord (black wire inside, red wire around the outside),

I presume you're referring to a power pack and the plug that comes out of it? Those are usually positive on the inside, negative on the outside so, yes, you've probably blown the regulator....

If you cut the insulation from it you will see the part number and can order a replacement although you will need to solder it into place.