I have a Battery pack that supplies 12V DC at 2A.
I use it to power 4 separate components:
my Arduino using a 5Volt Regulator (Using the 5V pin, I know this isn't recommended but I need to bypass the internal regulator)
my 12 Volt Magnetic Lock there is a fly-back Diode on this Maglock between the + - of the Magnet.
The Keyes SR1y relay that is controlled by Arduino logic through the A0 pin. Negative of Maglock into NC and COM into the NC of the Smart Relay below
An additional Smart Wifi Relay, used to turn off the Maglock in case the logic in the Arduino Fails (It's an Escape Room Puzzle, the logic relies on using appropriate RFID tags and readers to trigger the Magnet to turn off. I need to be able to trigger the Maglock remotely in case the reader fails or the users can't figure out the puzzle. COM of the Keyes goes into the NC of the Smart Relay, COM goes to Ground
Is this appropriate? Should I use additional Fly Back diode on the + - of the relays?
Everything has a common Ground. I don't se there being any problems but want an outside opinion.