Automatic switching on of arduino with two different sources using mosfets

[Adeyemi1071]

Hello everyone,

I have a setup that includes an arduino, a DC converter and a battery/ energy reservoir. I would like to switch off MOSFET controlling power from the DC converter to my arduino based on my algorithm and switch on the MOSFET that allows the system to be powered by a battery. However, my fear is that when the DC converter MOSFET goes off, the arduino cannot turn on the battery MOSFET. Please is there a better way to achieve this automatic switching as I am currently a newbie. Since i am trying to save power, i do not want to use a relay. I have attached a glimpse of my setup.

Sincerely,
Idris

 

[AnalogKid]

Measure or calculate the peak current drawn by the embedded system, and use that to calculate the value of a hold-up capacitor that goes between the cathode of the diode and the power input to the embedded system. To do this you need to know the lowest acceptable input voltage for the embedded system, and the average voltage at the input during normal operation.

ak

 

[cjdelphi]

I'll be honest I'm confused but what's new...

if you have 2 voltage sources with the same voltage, I would just wire up the outputs like this