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Figure 0 - Most of your parts inventory can be salvaged from old circuit boards
Most of your parts inventory can be salvaged from old circuit boards

In order to build an electronic circuit from plans or from scratch, you will need a number of semiconductors and components. Often, these individual components cost only pennies new, but in order to purchase from a large supplier there will be a minimum order number or price level that has to be met. It would seem crazy to pay $25 in shipping to receive a few 10 cent capacitors or resistors, especially when you can salvage them from just about any old circuit board. Almost all of the components I use are salvaged from old boards. I don't think I have ever had to order an odd value resistor or capacitor as I have always found what I needed by scavenging my huge junk pile.

A few dead TV or VCR circuit boards will net you enough raw components to fill an entire electronics parts bin, and allow you to experiment with varying values as you breadboard a new or published circuit from a schematic. Almost any discarded appliance that includes a power cord will become a great source of raw semiconductors, so tell everyone you know not to throw out their broken appliances, send them to your mad scientist lab for dissection!



Figure 1 - The basic tools you will require for any soldering or unsoldering work
Figure 1 - The basic tools you will require for any soldering or unsoldering work

A decent soldering iron will make your work so much easier, allowing the heat to be adjusted to the job at hand. Sure, you could do a lot with a $10 soldering gun, but when it comes to removing components or soldering small pin devices, the budget soldering iron may not be of much use. A fine point and a lot of heat will make component extraction very easy, especially on multilayered boards which require the heat to reach the inner copper layers in order to melt the solder. A soldering station with a heat control and interchangeable tips is one of those must have items if you plan to invest any time in the electronics hobby. A decent soldering station can be purchased at most electronics suppliers, and will range in price from $50 to $200, depending on what features and accessories it has included. If you soldering system does not include a sponge bath, then just wet an ordinary kitchen sponge with some water, as this will be needed in order to clean off the tip as it gums up with flux and old solder.

Large through-hole semiconductors can often be ripped up from old circuit boards using a soldering iron and your fingers to lift the parts, but there will be limits to this technique, especially on the smaller components or those with more than two or three pins. A desoldering tool, often called a "solder sucker" is essential for removing short lead semiconductors as well as those with multiple leads such as integrated circuits. This simple tool contains a spring loaded plunger that basically sucks up the heated solder, clearing the area around the lead and hole so that the part can be removed from the board. On most boards, it is possible to cleanly lift up a 40 pin IC in a few minutes so that it can be reused or even placed into a solderless breadboard. A solder sucker is also good for removing large components that have been placed down with a lot of solder to secure them to the board or transfer heat.

You will also require a spool of solder, even when unsoldering components as there will be times where you have to melt a bit of solder into a hole in order to use the solder sucker to clean up the hole. Molten solder is a liquid, so the transfer of heat between the newly added solder and the hard to reach solder stuck in the center of a multilayer board will allow the solder sucker to pull up every bit in one shot. For electronics work, you will need flux core (rosin core) solder, which is a thin, hollow solder with special anti oxidizing chemicals in the center that clean and protect the copper when soldering. There are various diameters of solder, with .032" being a good choice for all around electronics work. The type of solid heavy solder used for plumbing is of no use for electronics work!

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