I am wanting to use a L7808CV voltage regulator to drop my supply ( varies between 12 to 14v ) to 8 volts, to power a Mega 2560 board on the Vin pin. My thinking is that if I can supply a constant 8V to the Mega, its onboard regulator has less stress placed on it.
From research, I understand that I need 2 capacitors -- 0.33uF and 0.1uF
I have these components :
Radial Z5U ceramic cap,100nF 50V 5mm
part no : 5381449 from http://za.rs-online.com
KS radial Al electrolytic cap,0.33uF 50V
part no : 116975
I understand that the polarity of the capacitors is important. On the 0.33uF cap I can see the negative side printed, but on the 100nF ( is this the same as 0.1uF? ) I do not see any polarity markings.
Do I have the wrong capacitors ? If so, could you point me to the correct part numbers ?
Also, can I use the L7808 without the capacitors ? I recall that the Mega board has its own voltage regulator as it can accept up to 20V but runs on 5V.