Geiger Tube and Arduino Proper way to connect it to pullup Input?

Other Hardware General Electronics
1

Hey guys, hope someone can help, at the moment i have a SI-3BG Geiger Tube, wich i'm soon replacing with an SBM-20, i'm not really good with transistors lol, so i'm not being able to properly making the tube work, i connected it in a way that made it kind of work but had a lot of intereference.

(Maybe the tube could be defective or i damaged it somehow, but the SBM-20 is on the way, so i would like to have a circuit working to not damage the new one)

Can someone help me out and make a little circuit scheme on how connect and make it work with this bit of code? I'm using an arduino nano.

Basicly i have the D2 Pin in input pullup, when the geiger tube ionize it has to trigger the buzzer
For me this is not working at all or recieve random beeps, i'm not going to show my whole circuit since i'm gonna test it on a separate arduino to see if it works so i will just put this code and a buzzer.

For the 400V to the tube i have a DC-DC 5v to 1200V Converter from Aliexpress, not sure how good it is.
And a 10M Ohm to the positive of the tube, i use the 2n3904 Transistor, but i can replace it if needed.

pinMode(2, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(2), triggerGeiger, FALLING);

void triggerGeiger() {
       cps++;
       digitalWrite(buzzer, 1);
       delay(1);
       digitalWrite(buzzer, 0);
}

Thanks in advance if you are going to help, you rock.

TL;DR Need a proper circuit to read the impulses of the tube with the arduino.

2

Please post a hand drawn circuit diagram showing how you connected everything together.

This is a typical Arduino connection, but change the 220 Ohm resistor to 100K Ohms. Depending on the tube "count" current, you may need to increase R2.

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The Geiger tube power supply output must be well filtered and stably regulated in the range of 400-500V, or you will just get noise on the output.

3

That is how i connected in first place, i tried it again, with another arduino without anything else connected, in this case i get no noise, but the tube would not detect anything either, maybe it's the tube itself the problem

I don't remember what i did when it kinda worked because i changed it a couple of time to try and fix the noise, but it was not good anyway, the noise was here because it was all wrong, but the tube counted a few clicks when a radioactive source was near. Maybe i should just wait the SBM-20 and try again?

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Should be this: attachInterrupt(digitalPinToInterrupt(2), triggerGeiger, FALLING);?

5

Yes it is triggerGeiger, i deleted it in the paste by mistake, but in the code is correct

6

I don't remember what i did when it kinda worked

Keep a notebook.

That way you not only remember what you did, but you can ask a sensible question. There are plenty of circuits to try on the web. Some of them actually work!

7

You are right, as far as i remember, i moved the 10K resistor to the emitter and connected the capacitor here, and did something with the cables, it makes no sense but the tube gave some response this way instead of none, it should be working, the circuit is right, i tried many configuration and it does a few slow clicks, at this point i think this tube is not working as intended, but don't mind is quite cheap and insensitive.
Also if i gave more than 380V the tube goes in i believe it's called avalanche? when you get a storm of clicks out of nothing

With the SBM-20 Will probably work, i just hoped i could get this one working too so eventually i would have used it in another project, too bad there is not much info on this tube either because no one really use it