Power supply is only with batteries ?

[julienbayle]

Hi there,

I'd like to figure out if we can supply the MightyOhm Geiger Counter by using something else than battery.

Indeed, I'm aiming at this kit for an art installation that will be up for 1 month non-stop.
Any options are interesting...

Thanks

[julienbayle]

up ?

[r4ptor]

Yes it is possible.

I use mine with the 3,3V Pin from my raspberry. No Problems.

Have a look at your geigercounter. There is a pinslot namen Pulse. The pin with the triangle is 3,3V, the one on the other side(third one, not the one beside the 3,3V) is ground.

But remove the batteries before powering it with a steady source.

[julienbayle]

Hi Raptor.
In my case, I would like to use it with a computer only so that's not ok for me

Do you know how much time lasts 2 batteries with it ?

[mightyohm]

Hi Julien,

Instructions for powering the kit from 5V are here: viewtopic.php?f=15&t=3431#p5730
You will need to change a couple resistors, as described in that post.

You can power the kit from USB by connecting the USB power and ground to the PULSE header pins. You will need to modify a cable or add a USB receptacle to the kit.

Make sure you remove the batteries from your kit because if you apply voltage to the PULSE header when the batteries are installed you could cause the batteries to catch fire or explode..

[r4ptor]

Hi,

I have one question to the 5V mod. I did change the resistors and the kit works with 5V USB power, but now i get really low CPM and the measured values are very low.

have a look at the munin graph: http://0x42.dyndns.org/

before that, i usually had about the 8-9 times this values.

Is this an issue with the changed resistors?

[mightyohm]

Try increasing the HV adjustment slightly (about 1/4 turn) and see if that raises the count.

[r4ptor]

Didn't work, i think my geigertube is broken. I ordered a new one, hope this will fix the problem.

[mightyohm]

Ok. Please let me know if the new tube fixes your problem. Do you have a check source?

[r4ptor]

I will let you know.

No, not yet. But I will get one