This Whirly 100-Filament LED Lamp Is So Good

Nick of the Nick Electronics YouTube channel wanted to build a cool accent lamp and decided to get ambitious with it. Not only did his concept require 100 individual filament LEDs, but it also incorporated physical rotation for dynamic visuals. That came with many challenges, as Nick covers in his build video.

Nick’s idea was to stack a bunch of spinning discs to form a tower. Each disc would have filament LEDs mounted to it. So, there were two major challenges: spinning the discs and transferring power to the LEDs on the spinning discs.

That second challenge is a common one in many industries and the typical solution is a slip ring, which can pass electricity through contacts on a rotating joint. For this lamp, Nick attempted to make his own slip rings integrated into the PCB discs that host the LEDs. The first PCB in the stack has circular traces on its top side and the next PCB in the stack has spring contacts on its bottom side that ride along those traces. To get both the positive and negative sides of the circuit, there are two circular traces and two spring contacts per board.

That is logical in theory, but proved to be unreliable in practice. Any minor wiggle during rotation would cause at least one contact to stop touching its circular trace, causing power loss on that PCB and every PCB above it.

Nick then experimented with a couple of other solutions, including inductive coils and helical springs for better contact in both rotation directions, even with wiggle. But those didn't work well, either. Ultimately, Nick settled on simply running wires loose enough to allow for some rotation before binding.

Each disc has a slot, into which a pin from the preceding disc rides. The slots follow arcs along 45° of a circle. So, the discs all spin in sequence, offset by 45°. Combined with reversing rotation, the resulting staggered movement effect is mesmerizing.

Electronically, the rest of the build was pretty straightforward. Just a microcontroller, driver, and stepper motor on the top, with filament LEDs on the discs. There is dimming of the upper LEDs as a result of voltage drop, but I think that actually looks kind of cool.