Does anybody know the maximum current i can safely draw from the 3.3V pin on the arduino mkr nb1500? And what would happen if i draw more than the maximum?
Ya i understand. But i am powering multiple low current sensors which adds up. Therefore my question about the maximum current on this 3.3V pin.
Why not power the step up converter from whatever is powering the Arduino rather that the 3.3V pin ?
Because i am only taking a measurement every 10s to extend battery life, and the easiest way to do that is by letting the arduino sleep, which also cuts of the 3.3V pin.
I measured the current consumption and during the arduino sleep mode the 3.3V is definitely not drawing any current from my sensors. I might not be wording this correctly as i am not an electrical engineer
You can almost count on that. Here is the regulator data sheet: https://www.diodes.com/assets/Datasheets/AP2112.pdf
It says the output Imax is 600mA, but the problem is, that spec assumes the best possible heat sink. Tiny board like that one, have basically the worst possible heat sink.
Looking back at the thread, you're being asked to calculate the sensor load and report back for opinions. How about it?
One thing you could do, to judge, is start adding sensors one by one, and feel the regulator chip with your hands, until it's only getting a little warmer than without any. Then stop adding sensors.
It already supplies the other stuff on the board, so it will begin a little warm.
Questions like this are why EE's get the big bucks.
If you are not connected to a network and not transmitting, you can easily draw 250mA from the 3.3V
However, if you are connected and transmitting, I would not draw any more than 50mA.
So you need to know how much current all your sensors are drawing.
Looking back at the thread, you're being asked to calculate the sensor load and report back for opinions. How about it?
Well i am trying to reason the other way around. How many of my sensors can i actually use, i could leave some out if needed. So that could be anywhere between 10-100mA.
But i think i will assume 50mA on this 3.3V pin and test it for a while in a safe environment.