power

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.

NightHawkInLight shows how to make ultra-white radiative paint that cools surfaces below ambient temperature without electricity. He walks through the research papers and the household-materials process.

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.

Tech Ingredients shows how to build a liquid panel with a specialty paint that, placed outside, cools below ambient air temperature. It demonstrates radiative sky cooling.

Matt Risinger covers installing a Zehnder ERV fresh-air system in a tight passive house, explaining balanced ventilation, the benefits of heat recovery and the costs involved.

Ben Eater explains how a USB keyboard communicates, covering the electrical interface, bit and packet encoding, packet contents, and a comparison with PS/2.

A roughly three-hour screen recording of designing a barebones STM32F4 board in KiCad, covering schematic, four-layer layout and routing, USB and a buck converter. It ends with ordering manufacture and assembly through JLCPCB.

Ben Vallack walks through designing a custom keyboard PCB from scratch using Ergogen and KiCad, ending with a gerber file ready to order from a PCB fabricator. The example is a split keyboard.

A 100-minute tutorial from Phil's Lab on designing an STM32-based 'black pill' PCB in KiCad 6. It covers schematic capture, two-layer layout and routing, USB, and sending the board for manufacture and assembly.

Ben Eater explains how the PS/2 keyboard interface works, covering its clocked serial protocol and scancodes. He builds up the hardware-level understanding needed to read keypresses.

Markus Triska tours Prolog's most distinctive features, including its use as a database and query language, rule processing, constraint solving and compile-time rewriting. It also covers concise meta-interpreters.