--- title: USB-C Adapted For Legacy Sprinkler Systems | daily.dev description: A hardware hacking project from opensprinkler.org explores using USB-PD power to drive 24VAC sprinkler solenoids instead of a traditional transformer. Four... canonical: https://daily.dev/posts/usb-c-adapted-for-legacy-sprinkler-systems-javliktf1 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: USB-C Adapted For Legacy Sprinkler Systems | daily.dev og:description: A hardware hacking project from opensprinkler.org explores using USB-PD power to drive 24VAC sprinkler solenoids instead of a traditional transformer. Four... og:url: https://daily.dev/posts/usb-c-adapted-for-legacy-sprinkler-systems-javliktf1 og:image: https://api.daily.dev/og/posts/jAvLIktF1.png og:image:alt: USB-C Adapted For Legacy Sprinkler Systems og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # USB-C Adapted For Legacy Sprinkler Systems **[Hackaday](https://daily.dev/sources/hackaday)** · 2 min read · 1 upvotes · 0 comments ## Summary A hardware hacking project from opensprinkler.org explores using USB-PD power to drive 24VAC sprinkler solenoids instead of a traditional transformer. Four approaches are compared: unipolar PWM, dual voltage, synthesized AC wave from DC, and a bipolar square wave. The bipolar square wave method came closest to mimicking a true sine wave while placing less demand on the power electronics, offering a cheap, ubiquitous way to retrofit old 24VAC systems. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How can USB-PD power be used to drive a 24VAC sprinkler solenoid that normally needs a transformer? USB-PD power can replace a 24VAC transformer for sprinkler solenoids using one of four approaches: unipolar PWM, dual voltage, synthesizing an AC wave from a DC supply, or producing a bipolar square wave. The bipolar square wave method got closest to mimicking a true sine wave while placing the least demand on the power electronics, making it the most effective of the four for driving legacy solenoids. _Explore more hardware retrofit projects and USB-PD power hacks curated on daily.dev._ ## Similar posts on daily.dev - [Converting AC Irrigation Valves To DC Operation](https://daily.dev/posts/converting-ac-irrigation-valves-to-dc-operation-agjaygcey) · Hackaday · 0 upvotes · 0 comments - [Tiny C64 PSU Rejects Tradition, Embraces USB](https://daily.dev/posts/tiny-c64-psu-rejects-tradition-embraces-usb-ejkxaqkri) · Hackaday · 0 upvotes · 0 comments - [RS-485 Sprinkler Control: Scaling Irrigation Across The Farm](https://daily.dev/posts/rs-485-sprinkler-control-scaling-irrigation-across-the-farm-tqwdgkzmy) · Hackaday · 0 upvotes · 0 comments --- Tags: [#embedded](https://daily.dev/tags/embedded) [View this post on daily.dev](https://daily.dev/posts/usb-c-adapted-for-legacy-sprinkler-systems-javliktf1) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"USB-C Adapted For Legacy Sprinkler Systems","url":"https://daily.dev/posts/usb-c-adapted-for-legacy-sprinkler-systems-javliktf1","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/usb-c-adapted-for-legacy-sprinkler-systems-javliktf1"},"datePublished":"2026-08-31T15:54:30.239Z","dateModified":"2026-08-31T15:54:49.526Z","description":"A hardware hacking project from opensprinkler.org explores using USB-PD power to drive 24VAC sprinkler solenoids instead of a traditional transformer. 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