mud test

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.

The UK DVSA's one-minute guide to the hazard perception part of the driving theory test, covering when to click and how to score well.

Ben Krasnow of Applied Science explains how electrophoretic e-paper displays work and how he modified the driver firmware and waveform lookup tables of a 4.2-inch panel to reach roughly 3Hz partial refresh. It covers the tweakable constants in the refresh process and touches on colored e-ink microcapsules.

Dave Jones builds the Evil Mad Scientist discrete-component 555 timer kit, then tests it and explains the internal circuitry of the 555 at transistor level. He finishes with scope waveforms.

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.

Tech Ingredients builds a pair of large Voigt speakers and explains ported, transmission line and horn designs. It tests them in an anechoic chamber and uses constrained layer damping for the enclosure.

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.