Andrew 'Otis' Tubesing
Electrical Engineering Laboratory Manager [Home]

How-to Resources

Electrical Concepts - Theory and Analysis (UST original videos): YouTube playlist for the videos below

Digital Milti-Meter - How to use a DMM (UST original videos): YouTube playlist for the videos below

Components

Wire

  • Ampacity Chart for maximum current ratings of various wire sizes. Use the last column for insulated ("covered") wire. Wire ampacity is specific to the wire type. This chart is a basic amalgamation of typical wire types and should be OK if you are using general hookup wire found in the tool crib. Realize these are maximum ratings so choose the next larger wire size than the one that matches the maximum current you expect it to handle. If you have questions, ASK!

Connectors

  • "C-Grid" locking connectors for board-to-wire, wire-to-wire , and wire-to-panel plug applications: In stock at the EE lab manager's office.

    • Connector family overview  EE lab manager office stocks a variety of items from this connector system. Have a look at what the options are and see Andy for more details.
    • Male and female housings, available in various sizes (number of conductors), accept pins to make a full connector.
    • Male pins for male housings and female pins for female housings get crimped onto the end of the wire, then inserted into the housing to make a connector. A special crimper is available from the EE lab manager. Care must be taken to insert the pin with the right face aligned with the window so the pin-catch tab will hold it in the housing.
    • PCB shrouded pin header connectors are also available to connect housings to printed circuit boards. Straight and right angle versions are stocked.

Soldering

Wire Wrapping

  • A prototyping wiring method that is much more durable than a breadboard.
  • Use "perf-board" as your wiring platform (see below)
  • Wire wrapping tutorial (a quick-start guide)
  • Wire wrapping instructions (comprehensive guide)
  • NASA Wire-wrapping specs More good info here
  • Wire-wrapping video Not the greatest video but you can see how it works

  • Important tips:
    • Tack-solder your components to a perf board first
    • Use a variety of wire colors to make trouble-shooting and wire-tracing easier
    • Don't make sharp corners around pins in your wire routing (can cause shorts), leave some play in the wire
    • Know when it's time to get a PCB.
Circuit Boards

  • Printed Circuit Boards (PCBs) - Process and instructions (powerpoint show).

  • Perf-boards (AKA vector-boards) are boards with a grid of pre-drilled holes for you to solder your own circuit. READ BELOW for instructions!

    • Look here first: Perf-Board Tips A pdf slideshow I made to show the basic points.
    • How to use PERFBOARD to build a circuit (also called vector board) A reasonably good demonstration of how to use a perfboard effectively.

      • Discussion of various types of perf-board starts at 1:00.
      • The construction part starts at 3:45.
      • Notice how jumper wires are put on the same side of the board as the components (treat jumpers like components).
      • One bad technique shown in this video is the wires attached for parts are soldered directly to the board--it is much better to use connectors for this because wires soldered directly to a board that run elswehrer almost always break off, especially if they're left exposed. If you put it all inside a box where the wires won't get moved or bent then you're probably ok soldering them to the board directly.
      • Also, this project uses a perf-board that is much larger than it needs to be.

      • If you are using a breadboard with bare copper pads, they will be much easier to work with if you tin them first (not all of them, just the ones you want to solder to). This is a process where you coat each pad with a thin layer of solder before you populate and solder the board. It will make your joints easier to solder, heat will conduct through the parts more easily and the solder will flow better.

    • Introduction to Breadboards. This is a good intro to using breadboards. It has an image showing how the nodes are connected internally. It also provides a simple circuit schematic and what it looks like built on a breadboard.



Batteries

  • LiPo (Lithium Polymer) batteries require some special safety and logistical parameters. The links below are a good place to learn more about LiPo handling, charging, and safety.


Other

  • Wire splicing techniques: NASA Wiring Standards Opens to page 81 in this pdf for the general splicing section. The most commonly useful approach is the 'Western Union/Lineman Splice' on Page 84.

  • Truss concepts: A reference page all about trusses.