test design

Matt Risinger demonstrates a blower door test on a house, using a fan to measure air leakage and find where air gets in and out. It shows how the test reveals the quality of the build.

Shawn Hymel of DigiKey introduces KiCad and explains how printed circuit boards are manufactured. It is the first part of a beginner series that builds a 555 badge project.

Mathologer shows a simple idea, the commutator, that lets anyone who can solve the first layer design their own full Rubik's cube solution. The same idea carries over to other symmetric twisty puzzles such as the Megaminx.

ElectroBOOM's Mehdi Sadaghdar explains how a full bridge rectifier works, the building block of AC to DC converters, with his usual humor and a demonstration of the circuit.

The Thought Emporium shows how to receive clear images directly from GOES-15, 16 and 17 and Himawari 8 geostationary weather satellites with software-defined radio. It covers the extra effort needed to receive GOES data.

Ben Eater shows how to build logic gates out of transistors, including NOR gates. It is part of his clear hardware-from-scratch teaching style.

Kenneth Finnegan shows how USB-C Power Delivery trigger boards like the ZY12PDN negotiate 5V to 20V so you can power projects from a USB-C charger, including the color coding for each voltage.

The 8-Bit Guy explains how character LCD screens work and how to control them directly, first part of a series.

A step-by-step guide to building a lifter, a small triangular ionocraft made from balsa wood, aluminum foil and thin wire, powered by a high-voltage supply. It also shows high-voltage safety practices.

Bisqwit writes a NES emulator in C++ in about 15 minutes of tool-assisted, sped-up coding, narrated with captions. It shows an accurate emulator built with a compile-time generated 6502 instruction table. Part 2 covers compiling and running it.

Lock-picking YouTuber Bill Johnson (BosnianBill) explains how to choose a high-security lock and why, showing examples and comparing designs. It covers what makes some padlocks more pick-resistant than others.

This Old House's Ross Trethewey explains MERV filter ratings and how air filtration works, then shows how to build a localized DIY air filter, including a box fan with multiple filters.

Ben Krasnow of Applied Science shows how to make and test YBCO high-temperature superconductor with a kiln and eBay chemicals. He demonstrates flux pinning and shows a close-up of the crystal structure.

Jeri Ellsworth shows early steps of making microchips at home: cleaving wafers, removing native oxide, testing dopant type with a hot probe, and loading the furnace.