I need to come up with a solution for a voltage regulator to be used in a vehicle, regulating ~12V from the car battery to 5V used by Atmel AVR microcontroller.
I've found this schematic on the Internet:
While I understand the most part of how this circuit works, I have a few questions about it:
- What's the purpose of R30 resistor on the input side?
- Why are there two capacitors on each side of linear regulator LM7805? This answer to another question might be the answer I'm looking for, but I'm not sure about it. If this answer is related to my question and the use of two capacitors is to reduce resistance and inductance, why are such different capacitor ratings used (0.1 µF and 470 µF)?
- Taking a single pair of capacitors, why is one of them polarized and the other one is not?
- Are there any drawbacks if using capacitors with larger capacitance instead of those displayed on the schematic?
- Are there any drawbacks if using capacitors with larger break-down voltage instead of those displayed on the schematic?
Thanks in advance.