Breadboard Prototyping:

There are many ways to put together electronic circuits-- the toughest part is keeping track of where everything goes, and making sure that what is supposed to be connected stays that way.  One of the best ways to try new (prototype) circuits is by using a "breadboard."  It is designed to allow easy connections, which can be changed, and yet, are reasonably sound.  Breadboards come in many sizes and designs, but the one we will be using (Radio Shack part #     ) is ideal for the type of experiments we want to do.  The first step is to understand which holes on the breadboard are connected to one another by "traces" (metal conductors) hidden under the plastic.  These are designed to grab the wires that we will push into the holes.  While you can make your own wires, it is pretty tedious.  Fortunately, nicely color-coded jumper wires, with their ends already stripped, are available in small kits (RS #   ).  Once you spend some time breadboarding, the strategy of laying out your parts and the various jumpers needed to make the connections you want starts to make sense.

An additional plus, is that once you have a circuit that you are happy with, converting to a permanently soldered circuit board is easy.  By using a pre-drilled prototype board (RS# ) with the same layout as the breadboard, all the parts and jumper wires go in the same locations.

Why not use the breadboard as a permanent circuit board?

You can-- but then you cannot use it for other experiments.  Plus, breadboards are more expensive than pre-drilled circuit boards, and are never as sturdy and reliable as a soldered board.  The breadboard is great while you are testing and making changes to your circuit.  Once you have a finalized design, go with solder.

next-- the light byte