Bask In The Warm Glow Of DIY Incandescent Bulbs

September 26, 2018 by Dan Maloney 15 Comments

With most of the apparatus and instruments we now take for granted yet to be developed, the early pioneers of the Electric Age had to bring a lot to the lab besides electrical skills. Machining, chemistry, and metallurgy were all basic skills that the inventor either had to have or hire in. Most of these skills still have currency of course, but one that was once crucial – glassblowing – has sadly fallen into relative obscurity.

There are still practitioners of course, like [2SC1815] who is learning how to make homemade incandescent light bulbs. The Instructable is in both English and Japanese, and the process is explained in some detail. Basic supplies include soda-lime glass tubing and pre-coiled tungsten filaments. Support wires are made from Dumet, an alloy of iron, nickel, and cobalt with an oxidized copper cladding which forms a vacuum-tight seal with molten glass. The filament is crimped to the Dumet leads and pinched into a stem of glass tubing. A bulb is blown in another piece of tubing and the two are welded together, evacuated with a vacuum pump, and sealed. The bulbs are baked after sealing to drive off any remaining water vapor. The resulting bulbs have a cheery glow and a rustic look that we really like.

Of course, it’s not a huge leap from DIY light bulbs to making your own vacuum tubes. That’s how [Dalibor Farny] got started on his handmade Nixie business, after all.

An Artsy And Functional LED Filament Lamp

June 24, 2018 by Dan Maloney 14 Comments

Some projects end up being more objet d’art than objet d’utile, and we’re fine with that — hacks can be beautiful too. Some hacks manage both, though, like this study in silicon and gallium under glass that serves as a bright and beautiful desk lamp.

There’s no accounting for taste, of course, but we really like the way [commanderkull]’s LED filament lamp turned out, and it’s obvious that a fair amount of work went into it. Five COB filament strips were suspended from a lacy frame made of wire, which also supports the custom boost converter needed to raise the 12-volt input to the 60 volts needed by the filaments. The boost converter is based on the venerable 555 timer chip, which sits in the middle of the frame suspended by its splayed-out legs and support components. The wooden base sports a few big electrolytics and some hand-wound toroidal inductors, as well as the pot for adjusting the lamp’s brightness. The whole thing sits under a glass bell jar, which catches the light from the filaments and plays with it in a most appealing way.

There’s just something about that dead bug building technique that we love. We’ve seen it before — this potentially dangerous single-tube Nixie clock comes to mind — but we’d love to see it done more.

[via r/electronics]

Xerox Alto CRTs Needed A Tiny Lightbulb To Function

October 15, 2017 by Al Williams 61 Comments

In the real world, components don’t work like we imagine they do. Wires have resistance, resistors have inductance, and capacitors have resistance. However, some designers like to take advantage of those imperfections, something our old friend [Ken Shirriff] noted when he was restoring the CRT of a Xerox Alto.

[Ken] tried to connect a Xerox monitor to the Alto and — since it was almost as old as the Alto — he wasn’t surprised that it didn’t work. What did surprise him, though, is that when he turned the monitor off, a perfect picture appeared for just a split second as the unit powered off. What could that mean?

Keep in mind this is a CRT device. So a perfect picture means you have vertical and horizontal sweep all at the right frequency. It also means you have high voltage and drive on the electron guns. If you are too young to remember all that, [Ken] covers the details in his post.

He found that the CRT grid voltage wasn’t present during operation. The voltage derived from the high voltage supply but, mysteriously, the high voltage was fine. There was a small lightbulb in the grid voltage circuit. A 28V device about like a flashlight bulb. It measured open and that turned out to be due to a broken lead. Repairing the broken lead to the bulb put the monitor back in operation.

On paper, a light bulb lights up when you put current through it. In real life, it is a bit more complicated. An incandescent filament starts off as almost a dead short and draws a lot of current for a very brief time. As the current flows, the filament gets hot and the resistance goes up. That reduces the current draw. This effect — known as inrush current — is the scourge of designers trying to turn on light bulbs with transistors or other electronic switches.

However, the unknown Xerox power supply designer used that effect as a current limiter. The short 600V pulses would hardly notice the light bulb but if too much current or time elapsed, the resistance of the bulb would rise preventing too much current from flowing for too long. With the bulb open, the negative brightness grid provided an impassible barrier to the electrons. Apparently, the brightness grid lost power a bit earlier than the rest of the circuit and with it out of the way — or perhaps, partially out of the way — the picture was fine until the rest of the circuit also lost power.

We looked at [Ken’s] efforts on this machine earlier this year. Light bulbs, by the way, aren’t the only thing that changes resistance in response to some stimulus. You might enjoy the 1972 commercial from Xerox touting the Alto’s ability to do advanced tasks like e-mail and printing.

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Flash A Light Bulb, Win A Prize

June 25, 2017 by Dan Maloney 47 Comments

How many geeks does it take to flash a lightbulb? Judging from the list of entries in the 2017 Flashing Light Prize, so far only seven. But we suspect Hackaday readers can add to that total.

The goal is almost as simple as possible: build something that can flash an incandescent light bulb for at least five minutes. The system actually has to power the bulb’s filament, so no mechanical shutters are allowed. Other than that, the sky is the limit — any voltage, any wattage, any frequency and duty cycle, and any circuit. Some of the obvious circuits, like an RC network on a relay, have been tried. But we assume there will be points for style, in which case this sculptural cascading relay flasher might have a chance. Rube Goldberg mechanical approaches are encouraged, as in this motor, thread, stick and switch contraption. But our fave thus far is the 1000-watt bulb with solar cell feedback by Hackaday regular [mikeselectricstuff].

Get your entry in before August 1st and you’ll be on your way to glory and riches — if your definition of rich is the £200 prize. What the heck, your chances are great right now, and it’s enough for a few pints with your mates. Just don’t let it distract you from working on your 2017 Hackaday Prize entry — we’re currently in the “Wheels, Wings, and Walkers” phase, so maybe there’ll be a little crossover that you can leverage for your flasher.

Continue reading “Flash A Light Bulb, Win A Prize” →

How Many Inventors Does It Take To Invent A Light Bulb

March 20, 2017 by Steven Dufresne 41 Comments

Many credit the invention of the incandescent light bulb with Edison or Swan but its development actually took place over two centuries and by the time Edison and Swan got involved, the tech was down to the details. Those details, however, meant the difference between a laboratory curiosity that lasted minutes before burning out, and something that could be sold to consumers and last for months. Here then is the story of how the incandescent light bulb was invented.

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Reverse Engineering Ikea’s New Smart Bulbs

February 6, 2017 by Brian Benchoff 81 Comments

Over in Sweden, Czech, Italy, and Belgium, Ikea is launching a new line of ‘smart’ light bulbs. These countries are apparently the test market for these bulbs, and they’ll soon be landing on American shores. This means smart Ikea bulbs will be everywhere soon, and an Internet of Light Bulbs is a neat thing to explore. [Markus] got his hands on a few of these bulbs, and is now digging into their inner workings (German Make Magazine, with a Google Translate that includes the phrase, ‘capering the pear’).

There are currently four versions of these Ikea bulbs, ranging from a 400 lumen bulb designed for track lights to a 980 lumen bulb that will probably work in an American Edison lamp socket. These lights are controlled via a remote, with each individual bulb paired to the remote by turning the lamp on, holding the remote close to the bulb, and pressing a button.

Inside these bulbs is a Silicon Labs microcontroller with ZigBee support, twelve chip LEDs, and associated electronics that look like they might pass the bigclivedotcom smoke test. After tearing apart this bulb and planting the wireless module firmly in a breadboard, [Markus] found he could dim a pair of LEDs simply by clicking on the remote. Somewhere in these bulbs, there’s a possibility of doing something.

As with all Internet of Things, we must ask an important question: will it become part of Skynet and shut down the Internet, like webcams did last summer? These Ikea bulbs look pretty safe in that regard, as the bulb is inexorably tied to the remote and must be paired by holding it close to the bulb. We’re sure there are a few more interesting exploits for these bulbs, so once they’re released in the US we’ll take a look at them.

Retrotechtacular: The Aerolux Light Corporation

December 16, 2016 by Lewin Day 38 Comments

The humble incandescent lightbulb is an invention just about anyone born in the 20th Century is more than familiar with. But it’s not the be all and end all of lighting technology – there are neon lights, compact fluorescent bulbs, and even LEDs are finally being adopted for interior lighting. But with the endless march forward, there are vintage throwbacks to the past – how many hipster cafes have you been to lately with great big industrial-looking filament bulbs hanging from the ceiling?

Even when switched off, they have a striking appearance.

However, that’s not all history has to give us. These gas discharge bulbs from yesteryear are absolute works of art.

The bulbs contain delicate floral sculptures in metal, coated with phosphor, and the bulbs are filled with neon or argon gas. Applying mains voltage to the electrodes inside the bulb causes the phospor to fluoresce, creating a glowing flower that is hauntingly beautiful.

These bulbs were manufactured by the Aerolux Light Company, from the 1930s to the 1970s. Once upon a time, they could be had for as little as 20 cents a bulb – nowadays you’re likely to pay over $50 on eBay or Etsy. The bulbs work by the glow discharge effect, not at all dissimilar to garden variety neon lamps.

While it’s not easy, it is possible to make your own vacuum tubes. Maybe it’s time to order some phospor powder and a tank of neon and get to work? Be sure to document your attempt on Hackaday.io.

Thanks to [Itay Ramot] for the tip!