Recommended Materials
An Excel spreadsheet with a list of recommended materials and a board layout guide can be found on this page and is explained below:
• Solder - 0.032" diameter (or other fine) rosin core lead-free solder.
• Soldering Iron - An inexpensive soldering iron will do (from 25 to 40W), as long as the tip is very pointed. The pointed tip will allow you to get into tight areas, since some of the components are right next to each other.
• Desolder Braid - Face it! You will, at some point, mess up a solder joint and need to remove the solder. Desolder braid is thin braided copper that you place over the solder joint and then place the soldering iron tip on top of the braid. This melts the solder and sucks it into the braid via capillary action. This method is much easier than trying to use a solder sucker and the joint is left much cleaner.
• Multimeter - This is an invaluable troubleshooting tool. This can help you find problems with your wiring or components. You can find an inexpensive one at Radio Shack or Wal-Mart.
• Breadboard - Though you don't have to get a breadboard, with the layout that I have provided, I still recommend it if you havn't done this kind of thing before. A breadboard allows you to build the circuit and test it without having to solder everything together first. The components fit into the holes in the breadboard, which holds them in place and provides connections to other components. Some of the breadboard rows are interconnected on the bottom of the breadboard as well as are some of the columns, which provides the ability to interconnect components without using wires.
• Circuit Boards - A circuit board is a thin wafer drilled with many holes and has thin copper foil on one side. The foil provides the connectivity between components, just as the breadboard does.
• Stand-Offs - These are posts that hold the circuit board in place and above your mounting surface.
• IC Chip Sockets - This socket is soldered onto the circuit board and then the Quad Comparator is mounted into it. This protects the Quad Comparators from the heat of soldering and aids in replacement if the comparator fails. Make sure to get a 14 pin socket.
• Panel Mount LED Holders - Optional. If you use indicator LED's, these hold them in place once mounted into the circuit enclosure.
• External Plugs/Jacks - Having the ability to plug the phototransistors, start switch, parallel port cable, and power source to the circuit board is essential. Each one of these connections should be unique, so you cannot accidentally plug something into the wrong connection. Radio Shack carries a variety of plug/jack combinations that will work for this project, based on the number of wires that you need to connect. Suggested connectors are in the parts list.
• Wire - You can use 22 gauge wire for the connections between components on the circuit board. You should get the wire in more than one color. You can use the same wire for your connections from the circuit board to your external components (LED's, phototransistors, start switch, and power plug socket) or you can use wire such as phone wire. Phone wire comes in longer lengths and has different colored wires to use for each individual connection.
• Wire Strippers/Cutters - Make sure it can strip wire at least down to 22 gauge wire.
• Heat-Shrink Tube - This is flexible plastic tubing that insulates your wire solder joints. You can cut the tubing to size, place over a solder joint and using a heat gun or flame, melt the tubing down so it fits snugly. The tubing comes in a variety of sizes, so find the smallest diameter that you can and one size up from that.
This is easier than taping everything.
• Soldering Heat Sink - Optional. Based on your soldering skill, you may want to use a clip on heat sink to protect components like the regulator from getting too hot and becoming damaged. The heat sink clips onto the component and helps draw the heat away from the component during soldering.