Hi Arduino community!
Hope I'm posting this in the right section.The background spiel
I'll be needing 3 different voltages in my project for various components; 5v
for the AtMega328 chip, 3.3v
for a display module and finally 6v
for some servos. I also want to run everything of 1 singular power supply so I plan to use a mains supply/wall wart as it's not something that requires mobility.
I plan to remove the ATMega328 chip from the board and have it permanently fixed into my project at the end (this way I can re-use the board for a future project), so I can't really rely on anything that's already built into the board to achieve this.
My plan was to have a 12V 3A AC-DC power supply (a laptop charger) connected to a buck converter to step the voltage down to 6V 3A. This will provide power to the servos. I would then daisy chain a second buck converter to this to bring the voltage down further to 5V which would then power the ATMega328 + it's components (crystal etc...). From here I would then daisy chain a third buck converter to bring the 5V down to 3.3V for the display module (I may substitute this for a linear regulator as the current I need for the 3.3V part is very low; 20mA).
I was thinking of daisy chaining them in this manner, rather than having all 3 connected to the laptop chrager directly. I thought by doing this, the buck converters would have less voltage they need to drop when it gets to the 5V and 3.3V regulation (meaning less heat would be generated so I won't need to add any heat sinks or anything). From what I understand buck converters are very efficient and will not generate lots of heat like linear regulators can, but I thought this still may be worth doing.Questions
- By daisy chaining buck converters, does this cause any problems? For instance, current issues, heat issues or hazards? Is it better to have all 3 connected directly to the AC-DC plug, if so is there a reason?
- This one may sound completely silly. If the buck converter was rated for 3A max and the power supply says it can only provide 3A max, is there anyway to boost the current that is available after the buck converter? For instance for powering the servos I have 6V and 3A max after it's gone through the converter, but ideally I would like 6A to be available if the servos need to lift any heavy loads as each servo can potentially try to draw up to 1A each on very heavy loads.
- Slightly off the main topic here but, if I wanted to protect part of my circuit so it can never draw more than 2A, is there anything I can use to do this? I'm just concerned in very heavy loads where the servos may potentially try and draw the full 3A, this leaves nothing for the rest of the circuit (ATMega328 for instance) and will cause resets or other issues. So I was wondering if there was a way to limit this part of the circuit so it can draw between 0A-2A but no more than that, leaving 1A available for the rest of the circuit.
In case you need to know, the buck converter I planned on using has a LM2596 regulator.
Thanks you very much for your time and reading this, I look forward to your responses