Updated: Aug 21, 2020
Very small proof of concept design to show an LED array connected and powered in parallel from buck-converted 5v-to-3.3v USB power supply.
Because these are connected in parallel to a 3.3v supply, they run extremely bright as that's the high-end of the voltage range of these blue LED's.
I made this to understand fundamental electrical concepts about voltage and amperage. Before I built this, I'd spent about 2 weeks trying to understand conceptually how multiple components that would traditionally need a resistor on each component if paired with a power supply with a higher voltage than the components, would somehow work all connected together without a resistor on each one. This exercise helped show me the principals of electricity, how current and voltage flow through components and why/how, say, the very first LED doesn't surge with 10x more power than the last one since the electricity had to flow through that one first. It was honestly a wonderful learning experience because it got everything to just 'click' with me as I built it out.
The soldering job is awful looking because this was, at the time, the most sophisticated circuit I had ever built and the most amount of soldering I'd had to do for a project, so you could say I was a total beginner when it came to soldering skill at this point.
NOTE: This is one of my legacy projects that shows just the finished product, as I'm building this site out to document projects I completed in the past, but moving forward now that I have this site, I'm going to be working on walkthroughs that go step by step. All my 'legacy projects' that I only have the finished products of without walkthrough, will be notated with "(BuildLog)" in the titles.