We must build and test these solutions today, so they are ready to deploy when tomorrow’s emergencies strike. Now is the time to prepare for the future.
A firefighters works to stop a wildfire in Gouveia, in the Serra da Estrela mountain range, in Portugal on Thursday, Aug. 18, 2022. Authorities in Portugal said Thursday they had brought under control a wildfire that for almost two weeks raced through pine forests in the Serra da Estrela national park, but later in the day a new fire started and threatened Gouveia. (AP Photo/Joao Henriques)
In the modern world USB has become a truly universal connector, with its inclusion on almost every major piece of consumer electronics. It has even expanded well beyond things that we’d think of as consumer electronics, like the solenoids on automatic sprinkler systems.
This project comes to us from [Ray Wang] at opensprinkler.org who has been working on various ways of controlling the old sprinkler standards, which generally rely on a 24 VAC power supply to drive solenoids. This tests uses the power available from USB-PD and closely examines four methods of energizing the solenoids: unipolar PWM, dual voltage, synthesizing an AC wave from a DC supply, and producing a bipolar square wave. The bipolar square wave had some interesting results, being able to get pretty close to the behavior of a true sine wave while minimizing the dedrmand on power electronics.
For those working on old sprinkler systems, or many other antiquated systems that still rely on 24 VAC, this project shows that USB can deliver a surprising amount of power in unique ways, and the fact that it’s near-ubiquitous and affordable makes it that much easier to adapt into situations it was never really designed for.
UC San Diego researchers have developed inexpensive passive reflective tiles that could help mmWave 5G signals get around walls and other obstacles without requiring power.
Login
