Advice on using 12V power supply for electric door strike project

Projects General Guidance
1

Hello,

I'm just starting my first Arduino project and have done some research but can't find an answer to this question. I'm also fairly new to electronics in general.

I want to control a door strike with an Arduino (an Uno R3 for now). The door strike needs a 12V power source and draws 200mA. I have a 12V power supply that provides 1.5A (my multimeter measures 12.2V from it).

It is my understanding that the Arduino can be powered by a 12V source via the Vin pin. Will it therefore be a simple matter to use the same power source for the arduino and the strike? Am I better off using some sort of voltage converter to power the Arduino? Will there be any issue with sudden changes in voltage when the strike is activated?

2

If you are only powering the Arduino and one port (i.e. to source or sink for a relay coil), it should be ok to connect 12 volts. If you pass too much current through the on-board voltage regulator, it will generate heat, and too much heat can break down the VR, which will then fail, passing the voltage to the rest of the board. Hook it up and monitor the heat. You may need to add heat sinking if your circuit is power hungry. Or, regulate the 12 volts down to 7volts using a more efficient means before passing it to the VR.

3

OK, so if I was to add say a keypad, and a real-time clock, and maybe wifi, then I should drop the voltage?