Help for a Newb !

Hello everyone ! i'm very new to the forum, i've been a follower for some time because of my interest in multirotors but that lit a very old wick that has me back again wanting to learn more about code. I read a lot of pages here just keeping an open mind before i get started again. after reading many post i'm still on the fence about a power supply for my test rigg so with some help i'd like to figure out what's good for me !

  1. i'd like to have a flexable power supply on my bread board i figure some of my projects would be automotive based so i may need 12v to power a device for proper simulation i have a lot of laptop power supply's so i was thinking of building a regulator with common needed voltages to handle the task. is this a safe and stable method ? or will a desktop computer power supply work better ? it would save me time building and should be very stable.

  2. I have two boards on hand a Pro mini 5v @ 16mhz and a Mega 2560 of the two which would be better to use on my test rigg ? from what i've read the mega is overkill for a test rigg but the pro mini may not be the best board for a newb to start with if i'm wrong let me know ! it's size would save space on my rigg.

I have two boards on hand a Pro mini 5v @ 16mhz and a Mega 2560 of the two which would be better to use on my test rigg ?

We don’t know, because we don’t know what you want to do.

(sp. “MHz”)

i have a lot of laptop power supply

Some laptop supplies are quite high voltage, around 19V which will make your on-board regulator run hot.

The rigg is more for me to learn to write code so i figure after a while i'll need to learn how to combine things like lcd,leds,sensors,buttons,motors,servo's some electronics may need 12v i'd just like to have that on hand. As for the power bricks yes they are high in voltage but building a regulator would sovle that right ? or i could use the desktop powersupply it has few regulated voltage's yes/no ? last but not least, on the pro mini I stated 5v 16Mhz because it was the verison i have. it was purchased to use on a areoqaud setup but i went another route. if using the pro mini will present a learning curve or have limited capabilites then i'd rather use the Mega.

As for the power bricks yes they are high in voltage but building a regulator would sovle that right ?

A linear regulator (like the one on the Arduino board) will just burn the excess converting 19V to 5V as heat, so you'll need a DC-DC converter to get down to 5V if you don't want all that life-shortening waste.

i really thought about that too ! i didnt want to build a regulator thats why the computer powersupply looks very tempting i've used them in other projects.

If you're aiming for automotive use then I suggest you make/buy a robust regulator capable of producing a well regulated 5V from the 12V ish input.

For initial development, I don't see any reason not to use USB to power your rig. I expect you'd want to use USB anyway, for uploading and debugging your sketches.

I'd be wary of using a PC power supply, because some of them require a minimum load to be applied in order to maintain the output voltage.