DIY Geiger counter

[trixdropd]

Kidding mostly but have to ask?? 

[cloudscapes]

at its most basic!

[trixdropd]

A couple questions on that schematic..

What is the input and output? Also, what is the ic used?

[Taylor]

The in label is cut off - it's to the cap at the far left of the circuit. The answers to your other questions are contained in that schematic.

As I recall, there was a lot of trouble getting that to work. Plus, the supply voltages are not very convenient. For something truly like the  GC, DSP or microcontroller is a must. Spin FV1 is by far the easiest way to get into this.

You might also want to check out the "uncanny valley" thread. My circuits and Earthtonesaudio's contributions will get you in that territory much more simply than any other option I know of.

[trixdropd]

The in label is cut off - it's to the cap at the far left of the circuit. The answers to your other questions are contained in that schematic.

As I recall, there was a lot of trouble getting that to work. Plus, the supply voltages are not very convenient. For something truly like the  GC, DSP or microcontroller is a must. Spin FV1 is by far the easiest way to get into this.

You might also want to check out the "uncanny valley" thread. My circuits and Earthtonesaudio's contributions will get you in that territory much more simply than any other option I know of.

I don't see the ic name. Also, I should add that I'm talking a real gieger counter to count radiation. I'm assuming this is the gieger counter noise pedal?

[Taylor]

Ah, cloudscapes and I both thought you were talking about the pedal called the Geiger Counter, this being the forum for "building your own stompboxes". 

The ICs are both labeled in bold, directly under/over each chip: ADC0808 and DAC0807, but that won't be too useful to making a radiation particle detector. For that, here's a schematic I found:

http://www.imagesco.com/articles/geiger/schematicl.jpg

Note you need a geiger-muller tube.

[earthtonesaudio]

I don't see the ic name. Also, I should add that I'm talking a real gieger counter to count radiation. I'm assuming this is the gieger counter noise pedal?

BWAAAAHAHAHA!  I thought the exact same thing!  Wow you want a REAL Geiger counter.  That's awesome.  First thing you'll need is the input device, typically a Geiger-Muller tube (but in theory a generic gas-filled tube could do the job).  Then you'll need about a 400-600VDC supply.  After that it's trivially easy.  Just a comparator threshold that triggers a beep or lights an LED.  It's the tube and power supply that are the hard parts.

For more info maybe find a forum dedicated to building your own radionuclear test intstrumentation equipment, or your local university's physics department.

[Earthscum]

http://www.goldmine-elec-products.com/products.asp?dept=1468

There ya go. That should do it for ya.

[kurtlives]

http://www.goldmine-elec-products.com/products.asp?dept=1468

There ya go. That should do it for ya.

It's on sale! No way!

[frequencycentral]

For more info maybe find a forum dedicated to building your own radionuclear test intstrumentation equipment...

Don't we have a sub-forum for that?

[Ry]

Y'all might be interested in this:

http://www.sparkfun.com/products/9848

or if you want to roll even more of your own and just get the tube:

http://www.sparkfun.com/products/8875

[trixdropd]

You guys are hilarious! As for the ic, I meant the op amp triangles in the schematic. Don't see a label on them. They're ic's right?

[Hides-His-Eyes]

The Geiger counter schem shows 4049 inverter modules with triange-dots.

[culturejam]

I happened to see this in the last Goldmine Electronics ad flyer:

http://www.electronickitsbychaneyelectronics.com/

Not cheap, but they are real geiger counters. You know, just in case of a true SHTF (shit hits the fan) situation. 

[cloudscapes]

whoops 

[artifus]

You know, just in case of a true SHTF (sh*t hits the fan) situation. 

in which case maybe a method of detecting a possible means of escape would be in order?

http://3.bp.blogspot.com/_QEPCmku0Hrw/TUiC-piwWoI/AAAAAAAAAjU/oUlHZcm8M80/s1600/ufo_detector.png

[R.G.]

Since we're a DIY forum:

- Geiger-Mueller tubes are used to detect ionizing radiation.
- GM tubes work by the radiation ionizing a low-resistance trail through a dry gas between two electrode which have a high voltage between them.
- The gas, its pressure, and it's ability to quench the ion trail are important to getting a good GM tube operation.
- The casing around the gas and electrodes is important to what you can detect. The radiation has to be able to get through the casing of the gas to make ion trails.
- Gamma rays get through thin metal walls, so all of them detect gamma
- Beta rays are high-velocity electrons, and get through quite thin metal and most non-metals to some depth, so most GM tubes detect beta.
- Alpha particles are helium atoms, stripped of all their electrons. They are stopped by something as insubstantial as thick paper
- If you want to detect alpha particles, you need a GM tube with a special thin casing. Lest you think this does not matter, plutonium's emissions are almost entirely alpha particles. However, if you get plutonium particles into your body, the alpha is 100% absorbed by the tissue around it, and that tissue gets massive radiation burns. During the Manhattan project, immediate high amputation was the only known first aid for plutonium ingestion, inhalation, or contamination through the skin.
- GM tubes run on high impedance high voltage, generally 300-400Vdc, with a few meg in series. The sudden current jump when an ion trail happens is what causes the [clik] that we all think of as the classical sound of a geiger counter.
- GM tubes overload. When there is so much radiation that the ion trails cannot dissipate and have the tube come back to non-conducting, there is no reset to make the next click. So when it's overloaded, it goes silent.
- The ion-chamber "civil defense" radiation survey meters are much less sensitive than GM tubes. Basically, if the yellow civil defense radiation survey meters detect anything, you're already inside an area with lethal radiation density. It's kind of a "you're already dead, just still moving" meter.

I have a working 1960s Navy surplus Geiger counter that I fire up every now and then. I bought it after the incident a decade or so ago when the scrap yard worker in Mexico broke open a heavy lead container to scavenge the lead, and found a white powder inside that glowed slightly blue in the dark. He took home some of the power to his children for fun that night, and dumped the rest in the scrap steel bin. The power was, of course, radioactive cobalt and the lead container was the casing for a medical radiation source. The scrap steel was melted at a recycling plant and made its way into reinforcing bars for concrete use and bases for patio tables. No one died as I remember from the rebar and patio tables, but I think the scrapyard worker and his daughter did.

[trixdropd]

Thanks guys. Rg, thanks for the insight.

[Ben N]

Planning a trip to Japan? 

[LucifersTrip]

BWAAAAHAHAHA!  I thought the exact same thing!  Wow you want a REAL Geiger counter.

I knew it when he said "kidding" ...this one looks easier...and it's "low cost" and made w/ "commonly available parts" (except the Geiger-Mueller tube, of course) like 2N2222 and 555
http://www.galacticelectronics.com/Images/Schematics/GMCounter.PNG

gut shot...hahahaha