Fun-Size Geiger Counter Sits atop a 9-Volt Battery

Want a little heads-up before walking into a potentially dangerous radioactive area? Sure, we all do. But the typical surplus Civil Defense Geiger counter is just too bulky to fit into the sleek, modern every-day carry of the smartphone age. So why not slim down your first line of defense against achieving mutant status with this tiny Geiger counter (Facebook)?

We jest about the use cases for a personal-sized Geiger counter, as [Ian King]’s inspiration for this miniaturized build was based more on a fascination with quantifying the unseen world around us. Details are thin in his post, but [Ian] kindly shared the backstory for this build with us. Working on a budget and mostly with spare parts, the big outlay in the BOM was $20 for a Soviet-era SBM-10 tube, itself a marvel of miniaturization. While waiting the two months needed for the tube to arrive, [Ian] whipped up a perf board circuit with a simple oscillator and a CFL transformer to provide the 400 volts needed for the tube. The whole circuit, complete with tiny speaker and an LED to indicate pulses, sits neatly on top of a 9-volt battery. The video below shows it in action with a test source.

Geiger counters are not exactly rare projects on Hackaday, and with good reason. Take a look at this no-solder scrap bin counter or this traveling GPS Geiger counter built dead-bug style.

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CFL + Bugzapper = Battery Operated Camping Light


Knowing different ways of generating light is a great skill to have, so go ahead and add this one to your arsenal by combining a Bugzapper with a CFL Light Bulb.

Sure a CFL(Compact Fluorescent Lamp) works just fine on its own if you have AC mains, but what we’re talking about here is getting the light bulb to work off of a single D battery. We featured a similar hack a few months back by using a Joule-Thief to get the high voltage for the fluorescent tube, but if you can’t get your hands on discrete components, [Jan] shows us another way by gutting a tennis racket bugzapper for its booster board. Knowing that the bugzapper steps up the 3V to about 2000V, he decided to see if that same circuit would run off a single 1.5V D battery and achieve the voltage required to drive a CFL tube. After carefully removing the electronics from the CFL housing, [Jan] was able to directly connect the booster board to the electrode wires of the fluorescent tube, and voila; he now has a D-Battery operated camp light that has a run time of over 200 hours.

It would be interesting to see how this hack compares to the Joule-Thief method in terms of brightness and run-time. Before you go and scrap the parts out of the CFL light bulb, make sure you check out this detailed breakdown of popular CFL light bulbs.

Compact fluorescent grow light


Spring is on the way for our friends down under. With that in mind [x2Jiggy] built this compact fluorescent grow lamp to help start the seeds for his garden. He used materials that are easy to find, and multiple bulbs means that you can mix and match their color warmth in order to get the wavelengths of light best for plant growth.

He started by building the box out of MDF. It is lined mostly with a reflector meant to go in your car’s windshield when you leave it in a hot parking lot. He sealed the seams of the reflector using what he calls flashing tape. This is the rubbery type of stuff used as soft flashing around windows.

The bulb sockets came from an old string of party lights. Wiring is run through plastic junction boxes which keeps the setup code-compliant. Each of the CFLs draw 20 Watts for a total consumption of 160 Watts. Combine this with a DIY hydroponic tent and you’ll be eating fresh greens year round.

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Using incandescent bulbs to compensate for a slow start cfl

[Dick], like most of us, likes some pretty strong light in his workshop. He’s using CFL flood lamps to save a little energy. Unfortunately, he found that they gradually become brighter instead of that instant light he was accustomed to with his previous incandescent bulbs.

Not wanting to wait around for the lights to reach full power, but still wanting to save electricity, he devised a plan . He would install an incandescent bulb along side the others and fade it out slowly as the others became brighter. He acknowledges that he could have just put a 5 minute timer on it, but the transition would be abrupt and unpleasant. Instead, he built a circuit to get the exact result he wanted.

Just so you don’t miss it, the actual build is available to download at a link toward the bottom of the page.

[via HackedGadgets]

CFL Breakdown

Reader [Jay] was inspired by one of our earlier articles and started digging around the web for some more information, and found a handy web page with tear downs and schematics of popular compact florescent lamps.

Schematics are provided to 15 fairly common models including bigluz, isotronic, luxtek, maway, maxilux, polaris, brownie, Phillips, Ikea, Osram, and eurolight. Also, just in case you were ever interested in these little packages but did not want to open them due to sharp glass, mercury vapor, or phosphorus powders, photos are provided as well.

So if you need a few hundred extra volts to pack a little spark in your next project, need a 63rd way to cook your goose you should check this page out.

PCB light box in a scanner shell


[Kizo] repurposed a flatbed scanner to use as an exposure box for making printed circuit boards. Exposure time is controlled by an AVR ATtiny2313 microcontroller. The device is connected to a separate display board to control four 7-segment displays using one shift register for each. Time is set in ten second increments and once started, switches on the lights with a relay. Once the right exposure time has been reached, the lights are switched off and a piezo speaker is buzzed. There’s no mention of they type of bulbs he’s using but they look like compact fluorescent with tin foil beneath as a reflector.

If these are just CFL bulbs, how will the performance compare to a light box based around a UV light source?

[Thanks Jake]

Nixie Plasma ball


This one came out over a year ago and we missed it. [Daqq] has made a plasma ball out of a nixie tube.  All that was required was the transformer from a cold cathode meant for computers and a nixie tube. He did have to do a tiny bit of modification to the power supply, which you can see on the project page. This isn’t the most useful project, since you can’t really see much of the plasma, but it is really cool nonetheless. We think this would make a really neat button. You can see a video of it in action after the break.

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