The Electronics Of Cold War Nightmares

November 27, 2018 by Al Williams 8 Comments

It is a good bet that if you look around you, you’ll be able to find at least one smoke detector in sight. If not, there’s probably one not too far away. Why not? Fires happen and you’d like to know about a fire even if you are sleeping or alert others if you are away. During the cold war, there were other things that people didn’t want to sleep through. [Msylvain59] tears down two examples: a Soviet GSP-11 nerve agent detector and a Polish RS-70 radiation alarm. You can see both videos, below.

In all fairness, the GSP-11 is clearly not meant for consumer use. It actually uses a test strip that changes colors and monitors the color change. Presumably, the people operating it were wearing breathing gear because the machine could take quite a while to provide a positive output. Inside reminded us of a film processing machine, which isn’t too far off.

The radiation monitor looks more like a miniature version of an old floor-standing radio. The case design, the thick-traced, single-sided, hand-drawn printed wiring board, and the –by today’s standards — huge parts within all contribute to making this look like a piece of radio gear from the 1970s or even earlier.

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The Ins And Outs Of Geiger Counters, For Personal Reasons

August 12, 2018 by Dan Maloney 28 Comments

There are times in one’s life when circumstances drive an intense interest in one specific topic, and we put our energy into devouring all the information we can on the subject. [The Current Source], aka [Derek], seems to be in such a situation these days, and his area of interest is radioactivity and its measurement. So with time to spare on his hands, he has worked up this video review of radioactivity and how Geiger counters work.

Why the interest in radioactivity? Bluntly put, because he is radioactive, at least for the next week. You see, [Derek] was recently diagnosed with thyroid cancer, and one of the post-thyroidectomy therapeutic options to scavenge up any stray thyroid cells is drinking a cocktail of iodine-131, a radioisotope that accumulates in thyroid cells and kills them. Trouble is, this leaves the patient dangerously radioactive, necessitating isolation for a week or more. To pass the time away from family and friends, [Derek] did a teardown on a commercial Geiger counter, the classic Ludlum Model 2 with a pancake probe. The internals of the meter are surprisingly simple, and each stage of the circuit is easily identified. He follows that up with a DIY Geiger counter kit build, which is also very simple — just a high-voltage section made from a 555 timer along with a microcontroller. He tests both instruments using himself as a source; we have to say it’s pretty alarming to hear how hot he still is. Check it out in the video below.

Given the circumstances, we’re amazed that [Derek] is not only keeping his cool but exhibiting a good sense of humor. We wish him well in his recovery, and if doing teardowns like this or projects like this freezer alarm or a no-IC bipolar power supply helps him cope, then we all win.

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A Deadbugged GPS/GLONASS/Geiger Counter

April 26, 2015 by Brian Benchoff 38 Comments

So you think you’re pretty good at soldering really tiny parts onto a PCB? You’re probably not as good as [Shibata] who made a GPS/GLONASS and Geiger counter mashup deadbug-style with tiny 0402-sized parts.

The device uses an extremely small GPS/GLONASS receiver, an AVR ATxmega128D3 microcontroller, a standard Nokia phone display and an interesting Geiger tube with a mica window to track its location and the current level of radiation. The idea behind this project isn’t really that remarkable; the astonishing thing is the way this project is put together. It’s held together with either skill or prayer, with tiny bits of magnet wire replacing what would normally be PCB traces, and individual components making up the entire circuit.

While there isn’t much detail on what’s actually going on in this mess of solder, hot glue, and wire, the circuit is certainly interesting. Somehow, [Shibata] is generating the high voltage for the Geiger tube and has come up with a really great way of displaying all the relevant information on the display. It’s a great project that approaches masterpiece territory with some crazy soldering skills.

Thanks [Danny] for sending this one in.

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Artist Inadvertently Builds Hodoscope

March 6, 2015 by Brian Benchoff 31 Comments

A Hodoscope is an instrument used to determine the trajectory of charged particles. It’s built out of a three-dimensional matrix of particle detectors – either PIN diodes or Geiger tubes – arranged in such a way that particles can be traced along coincident detectors, revealing their trajectory.

This is not a hodoscope. It’s a chandelier. This chandelier is made of 92 individual Geiger tubes, each connected to a single LED fixture and a speaker. When a charged particle flies through the room and hits a Geiger tube, the light fixture lights up, a ‘click’ plays on the speaker, and the entire room is enveloped in light for a short moment in time. If, however, that charged particle continues on to another Geiger tube, the trajectory of the particle can be deduced.

The purpose of the installation – beside just being art or something – is to show the viewer sources of radiation and normal levels of radioactivity due to terrestrial and cosmic sources. Of course the spacing of these detectors is rather large – it’s made to fit in a gallery – and there is no connection between the detectors, making a coincident circuit impossible. If you want a real hodoscope, here you go.

This installation can be seen at the Burchfield Penney Art Center in Buffalo, NY through April 12. If you’re in the area, go there and eat a banana. Video below. Thanks [David] for the tip.

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Turning A Phone Into A Geiger Counter

June 23, 2013 by Brian Benchoff 10 Comments

geiger

We’re no stranger to radiation detector builds, but [Dmytry]’s MicroGeiger prototype is one of the smallest and most useful we’ve seen.

The idea behind the MicroGeiger comes from the observation that just about every modern smartphone can provide a small bit of power through the microphone jack. Usually this is used for a microphone, but with the right circuit it can be stepped up enough to power a Geiger tube.

[Dmytry]’s circuit uses a hand-wound transformer but keeps the part count low; there’s only a few dozen caps, resistors, and diodes in this build, making the circuit much smaller than the Geiger tube itself.

Since [Dmytry] is powering a Geiger tube with a phone, it only makes sense that he should also record clicks from the tube with an Android app. Right now, the entire project is still in the prototype stage, but everything works and his app can detect radiation from one of [Dmytry]’s sources.

The code and schematics for the MicroGeiger are available on GitHub, with a video of the project in action below.

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A Very Tiny Gamma Ray Detector

June 3, 2013 by Brian Benchoff 48 Comments

gamma

When you think of a radiation detector, you’re probably thinking of a Geiger tube and its high voltage circuitry. That isn’t the only way to measure gamma radiation, though, and [Alan] has a great circuit to measure even relatively weak radiation sources. It uses a very small photodiode, and draws so little power it’s perfect for projects with the smallest power budgets.

The detector circuit uses a miniature solar cell and a JFET wired up in a small brass tube to block most of the light and to offer some EM shielding. This, in turn, is attached to a small amplifier circuit with a LED, Piezo clicker, and in [Alan]’s case a small counter module. The photodiode is actually sensitive enough to detect the small amounts of gamma radiation produced from a smoke alarm americium source, and also registers [Alan]’s other more powerful radioactive sources.

The circuit only draws about 1mA, but [Alan] says he can probably get that down to a few micoAmps. A perfect radiation sensor for lightweight and low power applications, and gives us the inspiration to put a high altitude balloon project together.

Solar Powered Wifi Radiation Sensor

January 3, 2013 by Eric Evenchick 4 Comments

[Manish] packed lots of functionality into this radiation sensor module. The device is completely solar powered and weatherproof, so it can be mounted anywhere. It uses a Geiger Muller tube to monitor radiation and connects to the internet using wifi network to report the readings.

The design uses an Arduino Pro Mini to perform the monitoring and reporting. Wifi connectivity is provided by a RN-XV wifi module. A solar panel, Adafruit’s solar charger, and a LiPo battery are used to provide power to the device. It’s enclosed in Adafruit’s IP-66 rated weatherproof enclosure.

A custom Geiger Muller tube interface is used to interface with the tube. The interface is simple and cheap. It provides the high voltage required to drive the tube, and circuitry needed to detect the ionization events.

Once the device is connected to the internet, it uploads data directly to Cosm. This service lets the data be shared using Twitter, or accessed using an API. The project shows how to build a wireless networked sensor that directly connects to the internet for about $100.