Summary

This is a frame to hold several LEDs for using them to measure Planck's constant.

Print Settings

Printer Brand:

Prusa

                                            <p class="detail-setting printer"><strong>Printer: </strong>                     <div><p>i3 MK3</p></div></p>                                                                                <p class="detail-setting rafts"><strong>Rafts: </strong>                     <div><p>No</p></div></p>                                                                                <p class="detail-setting supports"><strong>Supports: </strong>                     <div><p>No</p></div></p>                                                                                <p class="detail-setting resolution"><strong>Resolution: </strong>                     <div><p>200</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>25</p></div></p>                                                    <strong>Filament:</strong> any? PETG

Post-Printing

Use:

            <div><p>This frame is designed to hold 13 5mm LEDs of various wavelengths.  The four medium holes are for electrical banana plugs.  I used copper tape inside them to make electrical connections.  </p><p>The LEDs are attached by placing the longer positive lead into the outer semicircle of holes and the shorter negative lead bent at 90 degrees twice into the inner semicircle.</p><p>The longer leads are bent and soldered together, connecting to the banana plug in upper right.  A current limiting resistor (200 ohms works well) is soldered in to connect this banana plug to the one near it.  This plug is then connected to the upper left plug, possibly through a variable resistor to adjust brightness.</p><p>A metal strip (attached by a 3mm screw) can touch the negative leads allowing switching.  The metal strip should be electrically connected (I used copper tape) to the bottom center banana plug.</p><p>Supplying about 5 volts to the upper left plug with ground on the bottom center plug allows lighting of the switchable LEDs.  The other two plugs are for measuring voltage across the LED and current through it (using ohms law to measure current indirectly: I=deltaV/R).</p></div>

LED Planck's Constant