design contest!

[Elie]

I just had an idea. We should have a design contest to see who can design the best metal detector circuit using the lm3909 LED flasher. The circuit should be centered around the lm3909, and using it as an AM radio does not count.

[Max]

I just had an idea. We should have a design contest to see who can design the best metal detector circuit using the lm3909 LED flasher. The circuit should be centered around the lm3909, and using it as an AM radio does not count.

Hi Elie,
it is a joke ???
Cause if not ...ehm I think you have to ask for a professional ...treatment.
Well...offcourse it's possible to make a metal detector with a led flasher...I saw some stuff on a french site...that uses a kind of led vu-meter ic to give strength indication of signal in a small PI design.
Using it as an am radio ...well...this could be a sanitarium issue for real.
Why don't use e.g. ZN414 or the ZN415 to do it...they are surely better though they have the auto-AGC that complicates things...I've designed a 2-box with one of these...(think was zn414) on long waves and it worked well...but then I dismantled it cause don't like 2-box detectors...

Best regards,
Max

[Elie]

Hi Elie,
it is a joke ???
Cause if not ...ehm I think you have to ask for a professional ...treatment.
Well...offcourse it's possible to make a metal detector with a led flasher...I saw some stuff on a french site...that uses a kind of led vu-meter ic to give strength indication of signal in a small PI design.
Using it as an am radio ...well...this could be a sanitarium issue for real.
Why don't use e.g. ZN414 or the ZN415 to do it...they are surely better though they have the auto-AGC that complicates things...I've designed a 2-box with one of these...(think was zn414) on long waves and it worked well...but then I dismantled it cause don't like 2-box detectors...

Best regards,
Max

Says the man with ABSOLUTELY NO IMAGINATION WHATSOEVER.

[Max]

Says the man with ABSOLUTELY NO IMAGINATION WHATSOEVER.

Hi,
??? me ???

Well...maybe...yes.

I'm for traditional electronics...ehm...the crap that doesn't work...
Can't win the nobel prize...but for sure don't mess with led flashers ...too furstrating

Kind regards,
Max

[porkluvr]

no junk

If designing around an -obsolete- device isn't crazy enough, then perhaps add the requirement for being solar powered. Better still, must be powered by back and forth sweep motion.

The winning entry will have the motion transducer aligned so that the unit stops working if swung like a pendulum. That way is better for teaching beginners!

Um, could I borrow the winner's?

[Max]

If designing around an -obsolete- device isn't crazy enough, then perhaps add the requirement for being solar powered. Better still, must be powered by back and forth sweep motion.

The winning entry will have the motion transducer aligned so that the unit stops working if swung like a pendulum. That way is better for teaching beginners!

Um, could I borrow the winner's?

Hi,
I suggest adding a step-counter...ehm...to the apparatus...cause many THs have too much weight...you know...they sits in mcdonalds...ordering piles os hamburgers before and after any TH run...and drink much coke...

Yes, offcourse...someone else would add a coke dispenser to their preferite detector...or a coffè dispenser...or...ehm...some other useful thing.

I'm for the "PURE DETECTOR IDEA" ! The one without a meter...the one without a working switch...the one without a speaker....BUT the one that , anyway, let me find something good buried object...AND NOTHING ELSE !

SO repeat slowly (100 times): I'm not a DANDY...I don't use my detector to acctract attention or to be cool on the magazines...I'm not a stilist...or a fashion designer...no need of fashion coils...fashion cases...fashion adesives...fashion cables...fashion power cords...fashion battery...JUST MY RUDE TREASURE FINDER!
(repeat like a MANTRA )

Best regards,
Max

[Elie]

Carl, can we get a ruling here?

[Max]

Carl, can we get a ruling here?

Hi Elie,
Are you serious about led flasher design ? What do you mean ?
Why a led flasher ??? Do you mean some pulsing strategy like in Sasho-Varna ib-pulse ?

Could be a good idea but I don't know why do it with a led flasher. ::confused::

Best regards,
Max

[Carl-NC]

I like the idea of using chips in ways they are not intended. PLLs (like the 4046) have been used as metal detectors, and Don Lancaster once made an LVDT chip into one. The 3909 looks a little sparse in comparison, could obviously make an oscillator but not sure what else. Unfortunately I don't have the bandwidth to indulge in such a challenge... sorry.

- Carl

[Unregistered]

I dont recall Don ever did,he however suggested others
to do it with the NE5521 LVDT chip!?

[Carl-NC]

You're probably right, he suggested it but never did it.

[Elie]

Hi Elie,
Do you mean some pulsing strategy like in Sasho-Varna ib-pulse ?

You have to decide yourself!

[Elie]

Unfortunately I don't have the bandwidth to indulge in such a challenge... sorry.

I did not mean that we should invite the whole world...

[Elie]

http://www.tinaja.com/glib/hackar2.pdf
pp. 19-23

[Elie]

I saw some stuff on a french site...that uses a kind of led vu-meter ic to give strength indication of signal in a small PI design.

Where did you see it?