What will this little device do?

[Merlysys]

It is to make back up camera and display work in the car.
Input is 12 volts from car battery, output is same voltage.

I tested and got those results so could it be some sort of filter?

What kind of waveform can I input to see it doing what it was supposed to do?

[fcb]

Probably just a big inductor (choke), or at best a double balanced choke.  The electrolytic forms a filter.

You won't see much of a 'waveform' unless you have a noisy car - it'll be difficult to 'scope both the input and output simultaneously in a meaningful way, but if you could, you'd hopefully see higher frequency noise on the output would be attenuated significantly.

[danadak]

Picture of board bottom would help.

Looks like diode is for input polarity protection.

Could it be a buck/boost regulator that always provides 12V if battery is below or above 12V.

Could be a simple transient suppressor (if transformer actually an inductor) for load dump.

Would have to see either schematic or part number for what the device is sandwiched between big cap and transformer/inductor.


Regards, Dana.