Take the humble LED filament light bulb, for example — I’ve never paused to think how they are made or why they look the way they look. Now, I’ll never be able to see them the same way again.

A Simple Over-Voltage Protection Circuit for LED Drivers This boost circuit implements current mode control and senses the LED current via resistor R14. The output voltage is boosted to just over 30V ...

For a 45-meter RG-58/U cable, the LED will flash at f1 = 1.67 Hz. When an open circuit is introduced at L2 = 25 meters from the IC, the LED will blink at about f2 = 3 Hz.