I try to test everything with my DVM after I salvage it but I don't have anything to test inductors and most IC's can't be tested without hooking them up to a test circuit. When salvaging old equipment, it is possible that there might be bad parts pulled from the PCB. My inventory list indicated that I had all of the parts I would need so it was time to draw up the circuit and start building. I've discovered that many data sheets include circuits that can be used as starting points for some very interesting projects.Īfter reviewing the parameters of the part and the example circuits I decided to come up with a circuit I could use to amplify an audio signal and drive a small speaker. And, the data sheet had some example circuits I could use to start with. ![]() That part had some possibilities for a fun project. I searched for a data sheet using the part number and discovered that the IC was a 5.8W Audio Power Amplifier. While salvaging parts from an old CD radio, I found a neat 10-pin SIP IC that was easily un-soldered from the circuit board. I also download the data sheets for semiconductors and integrated circuits so I have a way to understand what the part does, how to connect it in a circuit, and what voltages and currents the part can be safely operated at. Most times the pins end up pulling out from the bottom of the transformer rendering it mostly useless.Īfter I have removes the parts I want, I read the values and part numbers and keep a log of the inventory I have. I've had really bad luck with small ferrite core transformers in the metal can. I've had mixed success with 16-pin DIP IC's and iron-core Transformers. I've had great luck removing most Resistor types, Disk Capacitors, Mylar Capacitors, Electrolytic Capacitors, Transistors, Diodes, LED's, most push-button and sliding Switch types, and some IC's. Using gentle pressure, rock the component back and forth while watching the solder side of the PCB to verify that each pin moves freely.Ħ. Use a small standard screwdriver to separate the pin from any small film of solder holding the pin to the board.ĥ. Un-solder component leads with the solder pump. Use a small standard screwdriver to separate the pin from any small film of solder holding the pin to the board.Ĥ. Start by removing solder from any large ground pins or metal shields with the solder pump and then finish up with the solder braid. The rosin from the fresh solder also helps to clean the solder joint and makes de-soldering faster.ģ. I have found that adding fresh solder makes it much easier to cleanly remove the solder from the pad. Melt the marked solder joints with a soldering iron and add fresh solder to the pad. I mark the pads with a sharpie to help make sure I un-solder the right leads.Ģ. Identify the through-hole PCB pads that the part you want to salvage is soldered to. My process for removing the parts I want is:ġ. 60/40 Rosin Core Solder (Radio Shack Catalog #6400009) Desoldering Braid (Radio Shack Catalog #6402090)Ĥ. ![]() Desoldering Pump (Radio Shack Catalog #6400210)ģ. 25W Fine Tipped Soldering Iron (Radio Shack Catalog #6400206)Ģ. I use the following tools to remove parts from salvaged equipment:ġ. But as it is right now the amplifier works and sounds great. Before I call the project completed, I need to add a heat-sink to the amplifier IC and some vent holes in my project box. This Instructable is the project I built with a schematic from the IC datasheet and some parts I removed from an old CB radio. After he taught me how to solder and we completed the Velleman kit, he gave me a challenge to build an Audio Power Amplifier using only a schematic and a bunch of my salvaged parts. My uncle took me to Radio Shack and bought me some soldering tools, parts, a digital multi-meter, and a Velleman LED blinker kit to practice soldering with. But the rest have a good chance of being usable even after 40 years. In older equipment you have to be careful with electrolytic capacitors and some power resistors due to changing values over time. ![]() These radios have tons of useful parts like transistors, resistors, crystals, IC's, and ceramic capacitors. I got lucky and found three 1970's and 1980's vintage CB radios that weren't working. But in my area I have been successful obtaining recyclable equipment made in the 80's that have lots of components I can reuse. A lot of modern electronic devices aren't good candidates for part recycling due to the size of the components. A lot of people will gladly donate unwanted radios, stereos, CD radios, and other devices to someone like me that wants to learn and is willing to come get them. I enjoy salvaging electronic parts from discarded equipment.
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