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Slimming the Coaster

A project log for LED Coaster - Wireless/Batteryless

A new take on the LED coaster with wireless power charging and supercapacitor energy storage.

Scott ClandininScott Clandinin 08/09/2019 at 23:240 Comments

The next stage of the design will also be focusing on making a thinner coaster.

The coaster is about 11mm high. About 8.5mm of this is the 3D printed base, with about 1.5mm rising above the base for the curved finish of the resin.

With some rearranging and recessing, I can bring this total height down.

1. The potentiometer in the top left will be replace by a SMD resistor. I only included a pot in so I could test at different clock speeds.

2. The coil receiver circuit board can be removed and the components can be designed into my circuit board. The leads from the coil will be shortened to keep them low to the board.

3. Similar to the cut-out for the coil in the middle, I can leave a space for the supercaps to be recessed in as to not add height. 

With this arrangement, the highest component would either be the LEDs (2.1mm) or the inductor (TBD). I'll be safe and assume the highest component will be 2.5mm from the board. The calculation for a rough total height would be:

3D printed base + PCB thickness + highest component + resin overhang

0.7mm + 1.6mm + 2.5mm + 1.5mm = 6.3mm

With these design changes I would able to decrease the height by 4-5mm. 

Besides the better aesthetic of a slimmer coaster, it would also use a bit less casting resin and 3D printed material. The 3D printed material cost is mostly negligible but a decrease in print time would decrease the overall bulk manufacturing time if I were ever to try to scale up production.

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