Home Wires and Cable Design

Wires and Cable Design

New cables, wires and connectors get invented all the time. Usually these new cables replace some standard, or update a common method of connection. Inevitably each cable design fails to learn from the cables that came before it.

Basic Principals for Cable Designers

  • Cables should be designed such that it can be plugged in and out without looking at the cable. For example an RCA cable is fairly easy to plug in without looking because the cable is round and the plug for the cable protrudes from the device making it easy to feel with your fingers. S-video on the other hand is harder to connect because the cable could be rotated in any number of directions and the plug opening is flush with the device.
  • If multiple inputs are designed to go to the same place they should be desinged as one cable. For example HD Component cables have three cables that always go together. You would never want to criss-cross the cables or connect one but not all. Instead of having three separate cables you should design one single cable.
  • Don't reinvent the wheel - The world does not need another power cable connector or stereo audio plug. For some reason my cell phone provider decided to make a dedicated 8v power cable with an unusual plug that's incompatible with every other charger in the world. There's no good reason for this. If you're building a new technology that needs a different plug ok, but if there is an existing technology that can handle your technical requirements try to use it.
  • Don't fragment a new connector into multiple subsets- Some connectors such as Firewire and USB have several versions of the connector Small / Large / Male / Female, etc. It gets confusing. Pick a connector and stick with it.
  • Don't have cable polarity - It's hard enough for customers to find an Ethernet cable but to ensure that it's a twisted or not twisted is silly. How is an end user supposed to know what happens within the wire? The hardware should automatically figure out polarity and adjust the hardware accordingly.
  • Color code your connectons and cables - Try to color coordinate the paint on the end of your cable with the matching connector. A few years ago serial PS2 connectors for keyboards and mice started to get color coded with blue and green. This make it much easer to make the connection correctly.
  • Positive connection feedback - If possible try to provide audio or visual feedback when a cable is connected correctly. One of the things I worked on was audio feedback in Windows XP for device connections. When you're under your desk futzing with a cable in the dark hearing confirmation of your connection is very usefull. Same holds true for most other hardware devices.
  • Fail gracfully - If it's possible to connect the cable incorrectly or into the wrong place anticipate this and fail gracfully. If you can detect the wrong cable and provide on-screen feedback on how to correct the problem that's even better.
  • Transitive Cables - Try to enable transitive connections between devices. There are very few devices that have attempted this however if done correctly it simplifies both the wiring and the user experience. The idea is that if device A is connected to device B and device B is connected to device C then it's as if device A and C are already connected.
    A ---- B -----C
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