Hi, I've been creating some arduino nodes with nrf24l01 and some relays to control my room and now I want to power them when there is a failure on the main power, but need some help with the current readings i got from both nodes.
First, Node A:
normal operation :
With one of the four relays ON:
So, from what i understood, Node A is consuming 42.9mA on normal operation and 110.8mA with 1 relay ON, is that correct ?
Next, Node B:
and because with the red probe on the 200mA MAX (bottom right side) it couldnt power the electric door lock, i had to move it to 10A and now that's where current readings made me confused with eletric door lock ON:
http://imageshack.us/a/img812/6186/7kjb.jpg (scale 20m) it seems equal to the 10A scale shown above?! 0.5 ~ 0.49 ... CONFUSED :| http://imageshack.us/a/img837/7884/2tlk.jpg (scale 200m) also this doesnt make any sense to me
so at normal operation is consuming 55.9mA and it's consuming 500mA with the door lock on ?
With that questions answered i can understand what capacity i need for a battery. Since i'm powering those arduinos with 12v, i'm gonna look for a 12v battery and charger, correct ? (1) Now, i want them to work directly from a 12v charger (power supply) and , when there's a mains power failure, they detect the failure and work from the battery and disconnect from the battery when main power returns. (2) Also, i want that the arduino can detect if there was a power failure, or more simple, it knows when it's running from the battery. I'm power