Building a UV LED Circuit Correctly

Описание: Headline: Why Your LED Keeps Blowing Up! (DIY UV Resin Pen Repair & Circuit Math)

Ever wondered why some electronics use resistors and others don't? In today's video, I’m digging into an old UV resin curing pen that’s seen better days. After sitting in a freezing garage for years, the batteries are dead and the resin is a mess—but the "guts" of the device offer a perfect lesson in electronics.

In this video, we cover:

The Teardown:
Taking apart a precision resin repair tool.

Batteries in Series:
Why 1.5V + 1.5V isn't always just "two batteries."

Ohm’s Law for Beginners:
How to calculate the exact resistance you need using V = IR.

Identifying Components:
How to tell the positive (anode) from the negative (cathode) on a through-hole LED.

The "Circa" Rule:
Why these coin cell batteries don't need a resistor in the original factory design, but why my new 6V power source does!

Whether you’re a hobbyist looking to understand resistor color bands or just someone trying to fix a tool, this walkthrough will help you properly identify parts and calculate power requirements so you don't fry your components.

ShutterstockTimestamps:
0:00 - Intro: The frozen resin pen
1:35 - Precision teardown & switch mechanics
2:52 - Understanding batteries in series
4:09 - LED basics: Long leads vs. Short leads
5:00 - Why do we need a resistor?
9:15 - The math: Calculating Milliamps and Ohms
14:00 - Reading resistor color bands
17:30 - The final test: Success!
21:40 - Identifying circuit diagram symbols

🛠️ Key Formulas Used:Voltage:
V = IR

$Resistance:
R = V / I

(Amps):
I = V / R

The Magic Number:
6V / 0.02A = 300 Ohms

Gear used in this video:
Precision Screwdriver Set
Alligator Clip Jumper Wires
330 Ohm Resistors (Orange-Orange-Black)
UV Curing LED (365nm-395nm)

If you enjoyed this deep dive into electronics, hit that Subscribe button! I’ve got more videos coming on fixing broken gear and decoding circuit boards.

#electronicsunboxing #DIYRepair #UVResin #OhmsLaw #CircuitDesign #MakerMovement #HowToFix