Degaussing Coil To Restore Gameplay Like It’s 1985

October 15, 2018 by Steven Dufresne 24 Comments

You may think that cathode ray tube (CRT) TVs and monitors have gone the way of the dinosaur, but you’d be wrong. Many still have them for playing video games at home or in arcades, for vintage computing, and yes, even for watching television programs. [Nesmaniac] uses his TV for playing Super Mario Bros but for several years it had a red area in the top right corner due to a nearby lightning strike. Sadly, it stood out particularly well against the game’s blue background. His solution was to make a degaussing coil.

We have an article explaining degaussing in detail but in brief, the red was caused by that area of the metal shadow mask at the front of the display becoming magnetized by the lightning strike. One way to get rid of the red area is to bring a coil near it and gradually move the coil away. The coil has AC from a wall socket running through it, producing an oscillating magnetic field which randomizes the magnetic field on the shadow mask, restoring the colors to their former glory.

You’ll find [Nesmaniac’s] video explaining how he made it below. It’s a little cartoonish but the details are all there, along with the necessary safety warnings. His degaussing coil definitely qualifies as a hack. The coil itself came from a 15″ CRT monitor and his on/off switch came from a jigsaw. A 100 watt light bulb serves as a resistance to minimize current and if more or less current is needed then the bulb can be swapped for one with a different wattage.

To demonstrate it in action and give a few more construction details, we’ve included a second video below by [Arcade Jason] who made his for degaussing arcade game screens.

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Keeping Magnetized Marbles From Stopping The Music

February 2, 2018 by Dan Maloney 18 Comments

Take a couple of thousand steel balls, add a large wooden gear with neodymium magnets embedded in it, and what do you get? Either the beginnings of a wonderful kinetic music machine, or a mess of balls all stuck together and clogging up the works.

The latter was the case for [Martin], and he needed to find a way to demagnetize steel balls in a continuous process if his “Marble Machine X” were to see the light of day. You may recall [Martin] as a member of the band Wintergatan and the inventor of the original Marble Machine, a remarkable one-man band that makes music by dropping steel balls on various instruments. As fabulous a contraption as the original Marble Machine was, it was strictly a studio instrument, too fragile for touring.

Marble Machine X is a complete reimagining of the original, intended to be robust enough to go on a world tour. [Martin] completely redesigned the lift mechanism, using magnets to grip the balls from the return bin and feed them up to a complicated divider. But during the lift, the balls became magnetized enough to stick together and no longer roll into the divider. The video below shows [Martin]’s solution: a degausser using magnets of alternating polarity spinning slowly under the sticky marbles. As a side note, it’s interesting and entertaining to watch a musician procrastinate while debugging a mechanical problem.

We can’t wait to see Marble Machine X in action, but until it’s done we’ll just settle for [Martin]’s other musical hacks, like his paper-tape programmed music box or this mashup of a synthesizer and a violin.

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