Building a sound reactive EL panel and learning something in the process

We’ve seen a lot of builds using electroluminescent wire, usually in the realm of costumes and props. Unfortunately, most electrical engineers don’t deal with blinking and dimming EL wire and panels and any tinkerer trying to control electroluminescence doesn’t have a lot of resources on how to control EL stuff. [ch00f] wanted to fill this knowledge gap, so he build a sound reactive EL panel driver and learned a lot in the process.

Nobody really knows how electroluminescent wire and panels work on a molecular level, but [ch00f] did know that changing the direction of an electric field will cause the EL material to glow. Changing the frequency of this electric field will change the EL material’s brightness, so all [ch00f] had to do was make a variable-frequency EL driver – something that’s a lot harder than it sounds.

We won’t bore you with the details because we  couldn’t do [ch00f]’s write up any justice. We will skip to the end and tell you [ch00f] was able to make a sound reactive EL panel after a month of work that included making his own transformers and doing a whole bunch of math. You can check out the video of [ch00f]’s [Tony Stark]-esque EL panel after the break.

Continue reading “Building a sound reactive EL panel and learning something in the process”

There’s more than meets the eye to this robot car

This is a robot that any Transformers enthusiast will love. Sure, the car looks just a bit boxy, but you’ll forget all about that when you see it unfold into a bipedal robot (translated). [Zak Sawa] is responsible for the creation. He pull off the build using 22 servo motors which let the car transform, and provide the somewhat awkward ability to walk. Fold it back up again and the car can drive away. In other words, here’s the Transformers toy that you always wanted; radio controled and it actually works!

This is the result of about four years of work. Apparently it’s the eighth iteration, and a note on the video after the break teases a ninth version on the way. It’s not just the robot that looks great, check out the carrying case that houses it for storage.

Continue reading “There’s more than meets the eye to this robot car”

Burning plasma screen with breathtaking beauty


At some point you’ve got to resign yourself to the fact that the TV you’ve been trying to resurrect is just not salvageable. But if you’re knowlegable about working safely with high voltage, you might get quite a show out of it yet. Here [Aussie50] finds beauty in destruction when he fries a large plasma panel from a broken HDTV.

The flyback transformer from a microwave oven drives the display. The video after the break starts off kind of boring at first but before long it takes off. As portions of the display burn out the electric arcs jumping those gaps provide a thrilling view for the remainder of the 14 minutes.

Don’t want to commit to a video that long? Here’s a display that gives up the ghost after just four and a half minutes but we don’t think it’s quite as cool.

Continue reading “Burning plasma screen with breathtaking beauty”

Tutorial series shows you everything you need to salvage transformers from microwaves

Transformers certainly have a tendency to increase the cost of any project, especially if you need a large transformer to get the job done. Microwave ovens are great sources of free transformers, though they are not always in the shape required for your next build.

[Matt] put together three great tutorial videos covering the basics of salvaging Microwave Oven Transformers (MOTs), that anyone new to the process should watch before giving it a go. The first video covers MOT removal and disassembly, which is a time consuming yet easy process providing you follow [Matt’s] pointers.

The second video delves into transformer theory, and discusses how to achieve optimal performance when rebuilding an MOT or hand wrapping coils to fit your project specs. The third video in the series follows [Matt] as he rebuilds one of the salvaged transformers, documenting his pitfalls and successes along the way.

If you haven’t given much thought to salvaging MOTs, we definitely recommend taking a bit of time to watch the video series in full – it’s definitely worth it.

You can see the first video in the series after the jump – the rest can be found via the YouTube link above.

Continue reading “Tutorial series shows you everything you need to salvage transformers from microwaves”

Transformer-based PSU repair

Repairing someone else’s design mistakes is much more difficult than starting from scratch. So whenever we come across someone who’s good at this type of trouble-shooting we pay attention. [Jim] had a Sangean HDR-1 in his home. It’s a tabletop HD radio that stopped powering up for some reason. He cracked it open and got to the bottom of the problem.

The first order of business is disassembly, which isn’t too hard with this model. With multimeter in hand he started probing the transformer and found that the contacts for the primary are an open circuit; signaling a problem. There’s no inline fuse for protection, and further study of the secondary winding let him to discover the use of 1N5817 diodes. These are underrated parts for this particular transformer. He replaced them with 1N4003 diodes to bring the device in spec. But there was still the issue of fuse protections. A bit of circuit free-forming allowed him add a fuse and varistor  by soldering the directly to the transformer’s contacts.

Why stop there? While [Jim] had the case open he also swapped out the low-end op-amp and a few electrolytic capacitors to improve the sound quality of the radio. Op-amp replacement seems to be a popular way to improve the sound from HD radios.

Who knew Jacob’s Ladder builds had so many options?

[Grenadier] has a thing for the high voltage and, as you can see, he’s found multiple ways to build the icon of HV toys – a Jacob’s Ladder.

The three look similar, but they use different means of generation the voltages necessary to get a spark to jump through the air. The exhibit on the left uses a neon sign transformer, the one in the middle is based on a transformer from an X-ray machine, and the example to the right uses a microwave oven transformer. [Grenadier] discusses the pros and cons of each method, then links to his in-depth posts about working with each one them. There are also videos for all three. We’ve embedded the video for the microwave oven transformer after the break. That version of the Jacob’s Ladder requires some way to start the spark and in the video he’s doing it manually. There is always the option to add a solenoid to do the job but he does mention that you can’t just let it run because that cheap transformer will burn out before long.

If you like what you see here, perhaps you’ll be entertained when he runs HV through some soda cans.

Continue reading “Who knew Jacob’s Ladder builds had so many options?”

Tiny transforming beer can robot


The next time you reach for a cold one, you might want to take a look at the can to ensure that your beer won’t suddenly sprout legs and start skittering across the table.

You might remember [Ron Tajima] from some of his previous creations, including this Roomba-based baby cradle and the PacMan Roomba mod. This time around, he has created a cool little transforming robot that fits inside a beer can.

The robot’s brains are stored just underneath the top of the beer can on a custom-built board. On one side of this board, you will find an mbed controller which is used to manage all of the robot’s functions, and on the other side, four batteries provide all of the device’s power. The robot’s three legs are controlled by six servos, allowing for movement in several different planes. The beer-bot’s movements are controlled with a Wiimote, so we’re assuming he has crammed a Bluetooth module somewhere in there as well.

[Ron] mentions that it moves a bit slowly when standing on end, but we think the robot is pretty awesome as is, and we can’t wait to see what improvements the next version might bring.

Stick around to see a video demonstration of the robot in action.

[Thanks Sascha]

Continue reading “Tiny transforming beer can robot”