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?
It would probably work either way, but I would hook them all up to the same DC input voltage. Switching regulators may even be more efficient with the higher input voltage, they don't regulate voltage via heat dissipation in either case like linear voltage regulators do.
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?
No the converter cannot supply more current output then is available from it's input voltage source.
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.
Then just add an additional 6vdc buck converter and split the servo loads between the two converters.
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.
Not from the same converter. There are ways to add extra filtering caps and diode isolation if you end having this problem. These buck converter regulators are usually able to handle short 'overloading' situations as their chip usually has self protection functions inside them.
Lefty