LV5
Abiao builds color-changing night lights for his students (2222 likes): one 2000mAh 18650 + charge-management module (Type-C, 4.2V charge, 5V output) + switch + 0.01A color-changing LED, runs a month; nickel strip welded to +/− and folded flat, tape to secure; modeled and 3D-printed shells, three sets in 4 hours; given to the best students in the last maker class of the term; comments: no BMS, aren’t you afraid the kids blow it up? link for the LED?
Somehow ended up making a few fun color-changing night lights / mood lights as a gift for the students who took a term of the science maker extension class — a little present for the last lesson, tied to what we covered. Simple parts: a cell, a charge-management module, a switch and a color-changing LED bead; the LED draws only 0.01A, so one 2000mAh 18650 keeps it lit for a month; the goals were long runtime, fun color changing, durable, rechargeable, simple and cheap to make. Build: nickel strip is already welded to the cell’s +/−; fold the strip over so it doesn’t stick out, and a wrap of tape around the outside makes it more secure; the cell’s +/− go to the charge-management module, charged over a Type-C cable, the module charges the cell at 4.2V; the module’s 5V output goes to the +/− leads; the LED negative goes straight to the output lead, the switch sits on the positive side; test lit fine, decent brightness; loose parts look untidy, so model a shell, one print run of three sets takes over 4 hours; the two halves fit together seamlessly; three done (short on time). Over hills and around eighteen bends to the school; in class every student gets hands-on, small hands not yet skilled but earnest, helping each other, completing the circuit together and lighting their first light-controlled lamp; maybe one day this light will shine among the stars; the lights he made go to the best students; applause closes the last lesson. Comments (143): where to buy such a low-power LED, link? (5); Biao, when’s the next spot-welder sponsorship (why?); a cell must have a BMS, safety first / no BMS, aren’t you afraid the kids get blown up (creator replied); the charging port sits too low to plug in easily; a white shell would diffuse the light better; what brand of multimeter (ALIENTEK); how’s the welder / how much.
DIY an ultra-long-runtime seven-color night light? For the last science maker class of the term, I hand-built an ultra-long-runtime seven-color night light as a gift for my studentsProjectsRural Abiao