Hello Guys, I am trying to run bunch of relays, two arduino megas and one raspberry pi for one of my IoT home automation project. Not really sure what type of voltage regulators or any other voltage source I should use. For the main system I have a 24V 30A Power Supply. Now I want to use specific voltages for different components in the system. For raspberrypi 5V, for some sensors 3.3V, for two arduinos, 9V-11V each and for the relays power a 12V. I am kinda confused whether or not I should build linear voltage regulators for each of these use cases or use individual buck convertors for each use case or a buck/boost?. Or should I go for a zener diode voltage regulator solution? There's also a battery in the system which will provide power to all those sensitive components during a power outage which is very common in my country. I want to provide electricity(voltage and current) as clean as possible to my various sensors and the SoC and microcontrollers. Also efficiency will be very important in this case, because I have a battery in play. What you guys think would be the best approach? As far as I know, for the linear voltage regulators the efficiency is a crap. Then I also have to do heat management. But the advantage is the linear voltage supply with almost negligible voltage ripples. On the other hand buck convertors or even buck-boost convertors are very efficient but they have higher ripple voltages which I don't really want in my sensitive system. And zener diodes might be crap if used as the sole voltage regulator. But what about clipping and clamping the linear or buck-boost convertors with some zener circuitry? for clean and stable voltages and currents? My requirements for particular cases: 1. 5V3A - for raspberry pi 3 B+ with display. 2. [email protected] - for each arduino mega. 3. [email protected] - for the sensitive sensors and also lora modules at place. 4. [email protected] - for the 12V OMRON Relays 5. [email protected]~5A - for 50W Amplifier circuitry for voice control and feedback. Also, there might be two battery chargers that I need to use for the two gel cell battery pack I am planning to put for system backup. The two batteries might be 12V 5AH each connected in parallel to provide a total of 10AH backup. I am also not sure what circuitry or which type of charger I should use to safely charge these gel cell batteries for longest lifespan. Please do suggest if you guys have any idea on this too. Thanks.