How can I connect my 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.

 

[alec_t]

Welcome to ETO!

The whole thing I assume takes 12V power.

It is not safe to assume that. You need to check the specifications of the items shown.

 

[JonSea]

As Alec said, search for the documentation to determine what voltage it requires. But once you've figured it out, head to your local thrift store or PC recycler and look for a "wall wart" switching power supply with the right voltage and ample current. cell phone supplies provide 5 volts, and 12 volts is also common for old LCD monitor supplies and all other kinds of uses.

 

[jpanhalt]

It looks to me like it has already been connected to power -- too much.

What's the other side look like? Warranty? What's on the end of the "lampcord" (black cord with a white polarization stripe)?