Currently i'm bulding a circuit that need two voltages.
- 5V to feed the microprocessor, sensor, leds, LCD and others
- 12V to temporary feed small water pump (12V 4.8W) and a Electric Solenoid Water Valve (250mAh) [Activated by a MOSFET from MCU]
5V Will always run, but with a timeout that disable lot of sensors, leds, lcd, etc to save power, when user click any button it awakes. From x to x seconds it will auto awake to update sensors and values and sleep again.
12V will only be needed to turn on pump and valve by user interaction (Click a button) to fill a glass of water for example.
I have a 5V 5A brick power supply with stabilization that i run some of my projects. The main question here is if i use this power supply with some or one boost convert 5V->12V will be better than run 12V and buck converter to 5V to main system
Note: 5V Circuit can reach max 2A when its all ON and at Max Brightness