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 ?

...

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

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...

"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

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, <doh> 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.

"Mike"





**  LOL   -  so says a flat headed moron.





**  What ever for   ??

Got sweet fuck all to do with the thread.




.......  Phil

On Fri, 09 Mar 2007 11:44:14 GMT, "Blog the Haggis"



Most PCs already have an A/D input device.

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

...


Hi Andy,

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

I'll give it a try.

Cheers,

    -Duncan

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.

...



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.

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?

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.

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:
<http://www.vellemanusa.com/us/enu/product/view/?id50%0349