My first post here. I am fairly new to electronics and I’m building my own pyrography power supply. I have done a couple things to accomplish this but have not yet been successful. I found a tutorial online on how to make one using an Arduino and an ATtiny85 chip.
Here is my question: In the schematic, I can see that I need 2 resistors, but I don’t know what wattage to allow for R1 and what value to use for R2. I know that R2 is connected to an LED, but I don’t know the voltage that comes out of the ATtiny85 to calculate using the formula. Can anyone help me please?
Thank you guys for all the help. It clears a lot of my doubts. I’m not sure if I’m allowed to post external links, but here is the project I’m doing:
I already made a bench power supply and have a LTC3780 to have variable voltage and current. I thought this was going to be enough, as I am using the 12 V rail which carries 14 A, and I made a pen with nichrome wire. But it doesn’t work. It heats up, but it burns the fuse in my LTC3780. So, I decided to do the project in the previous link, to try my luck.
Thank you very much.