The more I read the more I know that I now nothing about this stuff…
the project, I want to make a smart power-strip (timer, IR remote, LCD, photo-resistor) to control lights or other devices put into the power-strip.)
I’m now building the electronics on a breadboard, to make sure it, and the code all work.
The problem: need moar powaa (using USB from PC now, which is causing issues)
what I want to do:
Connect a 9V 1A adapter to the Arduino, then connect a DC-DC converter to the Vin from the Arduino to convert from 9v to 5v. Then put the 5V output from the DC-DC convertor on the breadboard powerrail. And connect the negative to the arduino gnd to create a common ground reference. Is it better to connect the DC-DC converter directly to the 9V adapter? I don’t like to splice/cut the cable if I don’t have to. and I will not draw anywhere close to the 1A which is the maximum of the protection diode on the Vin of the arduino.
Then I still need some transistors. This is where I really have no clue what to get. there seem to be thousands or millions of them and they all have very similar specs. What is a good one for general Arduino use. I have a few TIP122 Darlington transistors, but there are so many others (2N3904, 2N3906, SS8550D, BC585,) I think the PN2222 is a good one to have around?
Is there any sense to be made of all these transistor part numbers? I’m looking for a switching transistor as opposed to an amplifying one.