When power is turned on, the circuit goes into standby mode, ... When reed switch is opened, pin 2 of Arduino goes high with the help of the pull-up resistor R2, and the alert signal is available ...

The first part is the ready-made Arduino Microcontroller board, and the second part is an interface circuit which can be wired on a piece of prototyping board. You can use any standard 9V battery to ...

As for the rest of what you said, I think that the low power consumption of soft latching circuits is usually acceptable, but for very low and high-power circuits a physical switch is best.

Another pin you can use on the Nano to power it up is the 5V pin (located on Pin 27, close to the VIN pin at the end of the board). This pin mostly serves as a power output pin that supplies power ...

Infineon has developed an Arduino shield to demonstrate the potential of its 24V Profet protected power switches. Called the Protected Switch Shield, it is also compatible with the firm’s own XMC ...