A/D Input Device for Windows

"Duncan"

** You want to do what ????

Try posting this on "alt.offwiththefairies.cranks "

........ Phil

What exactly is it that you want to do?

"dmm" < "Duncan" <

** Make himself a spectrum analyser for the whole RF band, of course.

Likely to use as a " bug " detector.

....... Phil

I'd like to capture the EM pulses from lightning strikes for use with a tracking program. There are a lot of hardware lightning detectors on the market but they are very expensive. I'm trying to find out whether it would be much cheaper to make a software based detector.

-Duncan

So basically you want to use something like a serial port to measure current/voltage ? via some hardware ?

You can get some good information on the front end - antenna plus signal conditioning - from an old scientific american article, back when they used to run the 'Amateur Scientist' column. Quite a few years ago, but if you go to a library that has back copies, the annual indexes had the amateur scientist entries separate, so shouldn't be too hard to find it. The lightning detector was one of their less lethal projects. Does anyone remember their copper oxide laser project? You couldn't imagine a better suicide device.

...

Yes I'm looking for something along those lines. I don't know much about PC A/D input devices but I assume they are mainly voltage based, meaning that I'll probably have to run the induced currents through a small resistor.

A standard serial interface would be fine if it was high speed but USB would be preferable. One of the experiment boards I listed had a USB interface but as I said it has much more functionality than I need.

Basically all I need is a dedicated voltage A/D device with at least 1 input that I can use with either standard serial or USB. I imagine the only other hardware that I will need would be an antenna and a resistor.

Do you know if there are any Australian electronics distributors who supply something like this?

-Duncan

"Blog the Haggis"

** Totally off with the fairies ....

** Totally off with the fairies .... ** The resistor ??

If this guy were not obviously delusional - it might just be funny.

....... Phil

Hi Bruce thanks for the feedback.

I realise that I could condition the signals using filter circuits but I was interested in exploring whether I could do this in the software. Basically all I am looking for is something equivalent to a simplified PC oscilloscope with one input.

I do have a PC oscilloscope but, like the experiment A/D input boards, they have much more functionality than I need. Do you know if there is a simple voltage input device for the PC on the market?

-Duncan

I recently built a ham repeater with a pc two radios and linux , the interface is a serial 4 port card which used to be sold for controlling phone lines like a simple pbx and works well , I would think that style of card would be close to your requirements but as to actually doing so is up to you . google as I did for more information I guess.

Most PCs already have an A/D input device.

Connect an AM radio, tuned between stations, to the line input of your sound card.

Lightning is fast enough that detecting it in software wouldn't be very reliable. (ie; you'd likely miss lots of strikes.) Any software based system would probably need some hardware assistance to 'stretch' or 'remember' the strikes from your detector. Are you planning on detecting strikes with an aerial or via ground pulses?

--
   W  "Some people are alive only because it is illegal to kill them."
 . | ,. w ,      
  \|/  \|/              Perna condita delenda est
---^----^---------------------------------------------------------------

I have one these kits that I built a while back & no longer need. It still works perfectly, & I'd be happy to sell it to you, if you're interested.

--
   W  "Some people are alive only because it is illegal to kill them."
 . | ,. w ,      
  \|/  \|/              Perna condita delenda est
---^----^---------------------------------------------------------------

What like this ?

no phil, you dont understand.

It is possible to log the emp from a lighting strike and the rising electric field from a storm long before there is a strike.

Can be used for warning of potential lighting strike so that mod of aged golf fanatics can be advised to stay indoors and play cards instead of overloading the local morgue...

For electric field suggest a small current mosfet with the gate being connected to a vertical "antenna" of about 300mm and a zener to ground to not let the mosfet gate punch and a high value resistor to bleed some charge away - from say 4Megs to 20Megs would be worth trying.

The mosfet source and drain are connected with a load resistor so that the voltage observed across the resistor gives:- a. A general electric field indication b. a sudden rise as associated with the emp from a regional strike.

The voltage can go into the sound card mic input with appropriate software to read that as a voltage - though I'm not sure if modern sound card mic inputs can read dc.

Ah - you can use the game port input as that can read a varying dc level :)

there must be s/w around the net to allow use of sound/game inputs for dc voltage measurement with logging I think :)

To insulate the antenna from local electric fields as you move around either keep it well away or put a pipe over it, not touching etc.

That would be a place to start, others might suggest some extra h/w but you wont need much if you can use the sound/game inputs. The mosfet and parts should be less than $10 oh and you might need an RF choke to remove any local readio stations that the mosfet might try to rectify etc...

--
Regards
Mike
* VK/VL Commodore FuseRails that wont warp or melt with fuse failure indication
   and now with auto 10-15 min timer for engine illumination option.
* VN, VP, VR Models with relay holder in progress.
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http://niche.iinet.net.au

"Mike"

** NO, that is you problem - dickwad.

" I'd like to capture the EM pulses from lightning strikes for use with a tracking program. "

" I'd like to capture the EM pulses from lightning strikes for use with a tracking program. "

" I'd like to capture the EM pulses from lightning strikes for use with a tracking program."

** The pathetically stupid OP wants to track strikes by direction finding on the EM noise radiated.

Learn to read, anytime.

........ Phil

I've been emailed by someone interested in buying this unit, so I'd better post the same correction here: My unit is actually the original version of the above kit, the K8055-1, which is very similar, but doesn't have as many digital I/O lines. Jaycar sells it under the catalog number KV3600, & full details (+ drivers & sample code) can also be found at Velleman's own site, at:

--
   W  "Some people are alive only because it is illegal to kill them."
 . | ,. w ,      
  \|/  \|/              Perna condita delenda est
---^----^---------------------------------------------------------------

...

Hi Andy,

Thanks for the suggestion, I hadn't considered using the sound card that way.

I'll give it a try.

Cheers,

-Duncan

Phil,

Bit onedimensional Phil ! Try to understand my post re the actual devices for detecting a strike or rise in field effect can be a useful pre-requisite to tracking the location of a strike, once you have more than one than you go the next step re timing, perhaps and array etc etc I didnt realise I need to fill in such a basic blank for youand you couldnt take it further...

Learn to think when it occurs to you, sometime soon please.

--
Regards
Mike
* VK/VL Commodore FuseRails that wont warp or melt with fuse failure indication
   and now with auto 10-15 min timer for engine illumination option.
* VN, VP, VR Models with relay holder in progress.
* Twin Tyres to suit most sedans, trikes and motorcycle sidecars
http://niche.iinet.net.au