technology

Technology Connections shows a cheap method for capturing analog video: a composite-to-HDMI upscaler feeding an HDMI capture dongle, aimed at digitizing home movies and VHS tapes.

A 1953 US Navy training film on the basic mechanisms in fire control computers: shafts, gears, cams and differentials. It shows how these mechanical parts compute ship and target firing solutions.

Ben Eater explains how VGA signals work and builds a breadboard circuit that produces correct sync timing so a monitor recognizes the signal. He then builds toward displaying an image from simple logic chips.

A short promotional video demonstrating a head-thumping technique that is claimed to relieve tinnitus. Covering the ears and tapping the back of the head is said to silence the ringing temporarily.

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.

A University of Michigan Medicine demonstration of building a cheap DIY air purifier from a box fan and a HEPA or high-MERV filter using hardware-store parts. It explains why this helps against dust, smoke and viruses and ties it to local air quality readings.

Tech Ingredients shows how to build flat panel speakers from exciters and foam board, with construction guidelines, measured SPL comparisons and a complete system playing music.

A roughly 45-minute vintage US military instructional film that gives a comprehensive overview of celestial navigation, covering sextant use and the theory behind lines of position.

Jerobeam Fenderson shows how to draw a mushroom on an oscilloscope in XY mode using stereo audio, then animates it by modulating with a larger wave. Pd and Max4Live patches are provided.

Ben Krasnow of Applied Science shows how to make small batches of specialty glass with minimal equipment, including designing and making photochromic glass. He covers ingredients, melting and the challenges involved.

Ben Eater finishes building a minimal VGA video card from logic circuits. He explains analog RGB signals, stores an image in an EEPROM and builds a simple digital-to-analog converter to display it.

Tech Ingredients shows how to build cheap, high-performance flat-panel speakers using audio exciters on sheet materials such as foam-core board. It explains how distributed-mode speakers work and walks through experiments to find good designs.

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.