Sorry if this is too n00b a question, I'm struggling to wrap my mind around basic EE terms for my project.
In my application I run 20 watts over a single AWG-24 wire at 5 volts. This works fine if the wire is <10 feet long; over 10 feet and my application fails; LEDs stop showing the proper color. According to those who have come before me, this is because of a "voltage drop".
I'd like to understand why something like Power over Ethernet (PoE) can send 20 watts hundreds of feet but my application cannot using a single AWG-24 wire. My intent is to roll my own solution leveraging the knowledge baked into PoE.
Suppose a PoE system uses a Cat5e cable. Cutting open this Cat5e cable reveals that it is made up of 4 pairs (cores?) of AWG-24 wires. The very same AWG-24 my application uses! I understand PoE's trick for sending 20 watts such a distance is that it steps up from 5 volts to 48 volts. Rumor has it that stepping up voltage means you can send power over longer distances.
Hold on though. I've heard there's something called Ohm's law that says if you increase the voltage you either need to decrease either the current or the resistance.
Since AWG-24 wires universally have the same resistance, the current must be going down in PoE! Yet PoE can still deliver 20 watts hundreds of feet away, so some kind of "combining" trickery must be happening.
What is this trickery? Is there some kind of black box that takes as input N (48 volt, M current) wire and outputs one (5 volt, NM current) wire?
Thank you kindly, community of experts, for any assistance you can offer me in my endeavor.
Is Ohm's law what punked me earlier? Voltage dropped because resistance increases as distance increases?
My understanding is the watts I so desperately crave are composed of volts and amps, and an amp is a way of measuring current. So many marvelous labels!