Documented alternative USB layout.

[physical.git] / misc / alternative USB layout / index.org

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+#+TITLE: Alternative (and incompatible) layout for USB connectors
+#+author: Svjatoslav Agejenko
+#+LANGUAGE: en
+
+* (document settings) :noexport:
+** use dark style for TWBS-HTML exporter
+#+HTML_HEAD: <link href="https://bootswatch.com/3/darkly/bootstrap.min.css" rel="stylesheet">
+#+HTML_HEAD: <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
+#+HTML_HEAD: <script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.5/js/bootstrap.min.js"></script>
+#+HTML_HEAD: <style type="text/css">
+#+HTML_HEAD:   footer {background-color: #111 !important;}
+#+HTML_HEAD:   pre {background-color: #111; color: #ccc;}
+#+HTML_HEAD: </style>
+
+* General
++ DISCLAIMER: I DO ELECTRONICS AND 3D DESIGN SOLELY AS A HOBBY. THERE
+  COULD BE ERRORS THAT CAN RESULT IN ALL KINDS OF DAMAGE. USE THESE
+  DESIGNS AT YOUR OWN RISK.
+
++ This design is released under Creative Commons Zero (CC0) license.
+
++ Authors:
+  - Svjatoslav Agejenko
+    - Homepage: https://svjatoslav.eu
+    - Email: [[mailto://svjatoslav@svjatoslav.eu][svjatoslav@svjatoslav.eu]]
+
+  - Valeria Agejenko
+
++ See also:
+  - [[../../index.html][Other physical projects in this repository]]
+  - [[https://www.svjatoslav.eu/projects/][Other projects hosted at svjatoslav.eu]]
+
+* Project description
+
+*Warning!* Here I describe a hack that I personally found useful for
+my own needs. But it is dangerous. Not to be replicated unless you
+know that you are doing.
+
+
+[[file:make.png]]
+
+I needed a way to power various devices I build.
+
+Requirements:
+
+- Reliable.
+- Cheap.
+- Easy to use.
+- Popular and highly available.
+- Ability to draw significant current directly from 12V cheap, popular
+  and powerful lead-acid battery (optionally off-grid). Useful for
+  powerful electric motors, heaters, soldering irons, radio
+  transmitters, etc.
+- Ability to draw limited but stabilized 5V power. Good for digital
+  circuits.
+- Ability to have limited and simple 1-wire digital communication.
+
+USB Type A connectors are best match that I found.
+
+The main problem is, I like USB connectors but I want to use different
+and incompatible electrical layout with them.
+
+*Connecting proper USB power supplies, devices and even cables to the
+ones that use alternative electrical layout would do damage!!!*
+
+To avoid accidental mismatches, I mark all connectors/cables and devices that
+use alternative wiring with [[file:stickers.png][printed, laminated warning stickers]].
+
+Alternative wiring schematic:
+[[file:schematic.png]]
+
+- Outer shell is ground.
+- 2 central pins are re-purposed to deliver +12V and high power.
+- 1 pin is for limited power +5V.
+- 1 pin for 1-Wire data.
+
+
+Example warning marking on device to indicate that alternative USB
+layout is used here:
+
+[[file:../lab%20heater%20and%20cooler/make,%202.png]]