Wiesserfalke:
I want to now how much peaks thear in a sekund to calculate how much raidiation thear is.Yes Im sure that it is 3kV becaus the gas only can ionizes bay 3KV
Tobi
I still need a diagram/schematic, or even some well taken photos (but photos are usually not enough)
BUT, I'll offer a shot-in-the dark with this (in case you're a person that can take an idea and run with it) [
****WARNING: EVEN THOUGH THE 3KV SUPPLY IS PROBABLY UNABLE TO PRODUCE MUCH CURRENT, IT'S STILL A VERY HIGH VOLTAGE, AND THUS POTENTIALLY DANGEROUS!!! PROCEED AT YOUR OWN RISK!!!!!!!!!!!]:
Now, I did a LOT of guessing, here. The values will, likely need to be altered -- especially if the current that goes through the Base-Emitter junction of that MPSA14 doesn't go low enough between radiation events. If so, an MPS13 might be a better choice (less Beta). And, you can also adjust the sensitivity of the transistor circuit, by proportionately decreasing the resistance values on the three resistors [the two 24k and one 47k]. Conversely, you can increase the sensitivity, to a point, by proportionately increasing the values.
So, what is going on in this diagram is this. IF there is a point where this mystery current is connected to ground, then cut that line [but first, remove power, then be sure to, using a 1MegΩ resistor, discharge any capacitance that might be holding high voltages], and insert the Base-Emitter junction of the MPSA14 transistor. What that will do, is allow the transistor to "monitor" that current path, and produce a low impedance turn-on event that an Arduino can read. BUT, this will impart a 2V drop at the insertion point, so if this will f-up your radiation detector, then DON'T DO IT. I can't tell because there is NO DIAGRAM/SCHEMATIC/OR EVEN A PHOTO! So, I'm kinda sticking my neck out, here -- hope you appreciate it ;D
I added that 24k/47k voltage divider (from the Collector to ground) because, when a Darlington transistor turns on, the voltage from the Collector to the Emitter can be as high as 1.5V, and that's right at the threshold of the definition of ON for a 5V Arduino. So, to make sure this has a chance in hell of working (and has decent noise immunity), I added the voltage divider to make sure it went low enough to be read as a LOW by the Arduino. It, also, serves to keep the voltage from going higher than 4.5V (worse case 4.7V). BUT, that only works if a solid 9V is applied to the Arduino Vin pin. If you don't know that a WallWart, that is not regulated, can deliver voltages higher than the voltage printed on the side, then for gosh sakes, slap a 4V Zener across that 47k resistor [Anode to ground) (I should have said "Regulated" 9V WallWart -- but I'm too lazy to change it!!!)
The point of the Opto Isolators (they are good to 15kV!) is to provide a safe path to a terminal, where you can display meaningful information about what is going on, on the other side of those isolators. For example, on the Arduino Serial Terminal.
The transistor output is tied to the Arduino's "INT" pin, so you can write an Interrupt Service Routine to capture the pulses that [hopefully] will occur there.
AND ONE MORE BIG WARNING: IN THIS CIRCUIT, THE ARDUINO IS NOT ISOLATED FROM THE POTENTIAL 3KV, SO WHEN YOU PROGRAM YOUR ARDUINO, BE SURE TO DISCONNECT IT FROM THE RADIATION DETECTOR!!! ONLY CONNECT THE ARDUINO TO THE RADIATION DETECTOR TO TEST IT!!! THEN DISCONNECT IT!!!!!! AT LEAST UNTIL YOU HAVE IT ALL WORKING AND THE ARDUINO BECOMES PART OF THE FINAL CONTRAPTION!!!!!!!
Also, if you don't know what you are doing, you could easily damage your computer's USB port, or even fry your computer!!! I would suggest doing this on a Raspberry PI that uses a relatively cheap TFT screen (so if it does go up in smoke, the loss won't be as great), and even consider powering it with a battery. For instance, one of these: http://www.instructables.com/id/Awesome-DIY-Raspberry-Pi-Laptops/