Nano external power supply

I am currently working on an autonomous DC motor car (standard project)

it worked perfectly until I got an external power supply from an adapter that supplies 12V that I attached to a 12V regulator with capacitors and checked the voltage with the AVO meter. I connected the 12v to the Vin and to the motors' driver with an L9110S H-bridge. both the arduino nano and the driver's led was on.

The weird part is the motors just twitches VERY faintly but works just fine when I plug the nano to the usb and then stops and twitches when I unplug it.

I have tried this with 5V, 9V, 12V to the Vin pin all from the wall adapter using regulators and capacitors.

How can I make it work without the usb from the computer??

Thank you

What is the current capacity of your supply?

Please supply a drawing of the circuit. Freehand and photographed will do.

Weedpharma

The max current from the adapter is 500mA. I know know that the current is too low, but what current should I supply for this circuit. Note: It's a low quality adapter.

Thank you

If your power supply is a DC regulated supply, why are you feeding it into another regulator?

Please give link to the driver board you are using.

How is it wired when "it worked perfectly......"?

Weedpharma