[glytch] sent in a tutorial on replacing dying capacitors on a motherboard, and we honestly can’t think of a better subject for an introductory tutorial. There’s nothing like having your friends think you’re a wizard for bringing broken electronics back from the grave. For the repair a dead motherboard was [glytch]‘s quarry. After taking a [...]

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If you’ve ever torn into very old equipment for a little refurbishment, you’ve seen ancient capacitors among tube sockets and carbon resistors. These caps are long past their life expectancy and are dried out. Putting a brand-new metal can cap in a piece of equipment from the 40s just seems wrong, though. Luckily, [unixslave] posted [...]

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[Bertho] really enjoyed pawing through the pile of projects submitted to the 7400 logic contest. But one thing kept hitting him with the vast majority of the entries: decoupling capacitors were missing from the circuits. If you’ve worked with microcontrollers or digital logic chips you probably know that you’re supposed to add a small capacitor [...]

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[Norman] put together a rather impressive 22,500 uF capacitor bank. In addition to find things to torture with the strong magnetic field generated by a sudden discharge, he’d like to measure the current pushed from the device. He’s found a way to do this using a digital storage oscilloscope. To protect the oscilloscope [Norman] built his [...]

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[Jeri Ellsworth] recently released another video in her “A-Z of Electronics” series – this time Capacitors are the subject. As a penance for my boneheaded AC Capacitor suggestion yesterday (I swear it was lack of sleep talking), [Caleb] suggested that I be the one to write this article. Since I’m not an electrical engineer (I [...]

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Audio Crossovers are an essential tool for any high end speaker system. Because most individual loudspeakers are unable to cover the entire spectrum of audible sound as well as multiple drivers are, it is necessary to split the input signal into low and high frequency parts. When a friend of [Anthony]‘s was about to send [...]

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The ceiling fan in [Steve Vigneau's] bedroom started giving him trouble. It is normally operated using a remote control but that functionality had become pretty spotty. He cleaned the contacts on the remote but still had troubles that could only be fixed by power-cycling the fan itself. When it finally died he set out to [...]

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What weighs more than 500 pounds, produces 500 kilovolts, and we don’t recommend you try at home in any way shape or form? If you guessed a rock disaggregation device, you’re correct! We also accepted lightning generators as correct answers. Using high voltage electricity, a rock can be split apart down to its grains without [...]

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[Daniel's] homemade digital picture frame looks great, it’s well-built, and it has a nice set of features. It’s not made from a broken laptop and he didn’t build it around a microcontroller. Instead, he saved a 19″ LCD monitor with a burnt out back light caused by the extremely common blown capacitor problem. Twenty dollars on eBay [...]

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[Daniel Eindhoven] put together this 11,344 Joule capacitor bank that he says would be perfect for weapons such as a rail gun, coil gun, or electrothermal-chemical gun. He machined a couple of aluminum plates to act as a positive and negative bus. The two are separated by a denuded sheet of PCB (making us wonder [...]

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Ever wondered how expensive versus cheap multimeters hold up to abuse? [Dave] gives us a pretty good idea by, well, blowing them up. He’s using a capacitor bank to put roughly 4.2 KiloVolts into the poor little meters. If you absolutely must skip to the multimeters, go to about 5:00. You really will miss out [...]

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Here’s an interesting idea: replace a disposable coin cell battery with a capacitor in order to filter the noise from an external power supply. [David Cook] is taking advantage of the falling costs of digital calipers. He’s mounted one on his milling machine but noticed that with an external power supply the readings would sometimes [...]

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It’s nice to have tip put on our desks that we think everyone, yes everyone can enjoy. The Transistor Clock is just as its name implies, A clock that doesn’t rely on ICs. 194 Transistors, 400 resistors, 566 diodes, and 87 capacitors are all that makes this clock tick – no programing, and most importantly [...]

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[Rp181] is at it again with version 2 of his rail gun project. The original did have some power with 18 400V 3900uf capacitors, but he’s ramped it up to now using 40! Reaching more than double the amount of joules of energy, 12kJ vs. the 5.6kJ! Some other changes include a new injector solenoid [...]

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[Fritz] built this 600 joule capacitive discharge spot welder in a case scavenged from a Lincoln plasma cutter. All of the circuitry was designed by [Fritz] and the schematics are available on his website. He has a few other welding related project also documented on his site that are worth checking out. While this isn’t the first homemade spot welder we have [...]

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