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Power supply is only with batteries ?

Posted: Mon Apr 28, 2014 1:42 pm
by 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

Re: Power supply is only with batteries ?

Posted: Wed Apr 30, 2014 12:03 am
by julienbayle
up ?

Re: Power supply is only with batteries ?

Posted: Thu May 01, 2014 10:48 am
by 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.

Re: Power supply is only with batteries ?

Posted: Fri May 02, 2014 7:48 am
by 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 ?

Re: Power supply is only with batteries ?

Posted: Sat May 03, 2014 3:19 pm
by 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..

Re: Power supply is only with batteries ?

Posted: Sat May 24, 2014 3:17 am
by 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?

Re: Power supply is only with batteries ?

Posted: Sat May 24, 2014 8:30 am
by mightyohm
Try increasing the HV adjustment slightly (about 1/4 turn) and see if that raises the count.

Re: Power supply is only with batteries ?

Posted: Sat May 24, 2014 12:49 pm
by r4ptor
Didn't work, i think my geigertube is broken. I ordered a new one, hope this will fix the problem.

Re: Power supply is only with batteries ?

Posted: Mon May 26, 2014 7:47 pm
by mightyohm
Ok. Please let me know if the new tube fixes your problem. Do you have a check source?

Re: Power supply is only with batteries ?

Posted: Tue May 27, 2014 9:24 am
by r4ptor
I will let you know.

No, not yet. But I will get one