first of allI'm sorry for my english.
I'm starting with electrical circuits (this is my first circuit) and I'm trying to create a Power Supply for an Arduino with battery backup.
Searching I've found three ways:
- A diode on every source to switch to the higher voltage source.
- Using a relay to switch when the main fails
- Using a Mosfet and a Transistor to swith when main fails
The first works while the main Power Supply has an higher voltage, but both circuits has similar voltages and maybe sometimes the backup circuit will have higher voltage.
The second works perfect, but the relay uses an high power (about 4 times the arduino comsumption) and I want to create a low power circuit.
The third seems to work but for now I don't have materials to test the circuit and I want to ask if is OK and/or can be better, before buy all the things i need.
Searching I've found some info and I've done a prototype on a program that looks like this:
I've done some tests with the program and seems to work, but are not truly real (even the stabilizer has it's own power on that program…).
With this circuit I want to avoid the stabilizer comsumption while is on battery to last as log as possible, then I need to separate both circuits (D2).
This prototype is OK or I've to change something?. Someone knows a better way to do it?.
I take this opportunity to ask for a program to make better tests before build a circuit. I'm using LiveWire now.
Thanks!!
Best Answer
Finally I've found this circuit that have lower voltage, but the rechargeable battery is better:
P channel mosfet battery charging/power selection circuit help
Greetings and thanks!!