Upgrading Victoreen CDV-700 6B Geiger counter with Arduino [solved]

Hello, I have an old Geiger counter from the Cold War that I use to survey things that emit small amounts of radiation like granite, background, clay pots, radion in basements (none yet), and other things. Having a Geiger counter so old means that there is a lack of a digital interface. It is all analog. If I wanted to measure the radiation of things that barely produce radiation I must count each count individually and I must count thousands of count for hours to get a low amount of error.

Anyway, science things aside I have used and programmed Arduino before but I have never tried to take input from a device that runs on a completely separate set of rules. The counter does have a candidate for an input for the Arduino, the phone jack however a simple true or false ohmmeter cannot be used because of a lack of digital logic meaning the circuit is always closed. Here is some info on the kind of output.

  • The volt range of the counter is between 0.5 - 2 volts on each count.
  • There is constant static due to the transformers.
  • When there are two or more clicks in close succession the voltage may not drop off of the 0.5 - 2 volts range.
  • When there is an occasional click it will always go above 0.5 volts but not much higher.
  • Ask questions for more info and I will answer them if I can.

That is all the info I can think of adding so here are my questions.

  • Does anything come to mind when reading the general problem?
  • Where should I start tutorial wise?
  • What should I Google?
  • Is there any digital logic, ICs, etc. I should look into?
  • What are some tips or tutorials for someone building their first complex circuit?

Try putting a capacitor and resistor in series with the earphone output. That will get you only the click and not the DC level problem you mention.

Paul

Adding a resistor and some capacitors seems to help with the analog determining what level it is at but I need to try a few different combinations of resistors and capacitors because sometimes the voltage stays too high and the other clicks get lost.

The Geiger counter's phone jack must be plugged into the Arduino's ground with no other connections. Any other component must be powered with an external power source with its own ground. No caps or resistors are required.