CoinHawk-very interesting !!!

[hawk17966]

Anybody made this CoinHawk?
Brief looking on schematic makes me think that it is
very interesting,
Since i mostly prefer coinshooting i would like to
make it.
But i am wandering my self is it all right...maybe some
mistake? Maybe bogus?
Any experiences?
Maybe someone have already .pcb file for it?
I would like to exchange something for .pcb for this
project and hints about it.
I had a lot of problems to extract it from .pdf and
put in useable .jpg.....
I am not expert in dealing with Adobe Acrobat so only
way to make .jpg from .pdf was for me to use SnagIt and
very slowly, part by part to copy/paste all schematic...
It was very hard...
Any hint for future, is there any other way to "steal"
schematic from .pdf document and put in .jpg or .gif or
any other format? It would be great help for me and i guess
others here....
Also i noticed there is no any negative (VDD) source in
schematic...maybe omited?
Positive(VCC) is wired properly,but labeled as ..7905.???
Negative (VDD.....) is missing, althoug only that part-
power supply is not buging me at all.It could be done
in many ways,some better than present one.
So,if there are interested persons here, c'mon lets
do this project togather...

Carl can you help here?
By the way, what's new in Maxim?
Which sector you are working in?
Remember Max232? Nice convertor it was!

[robert]

Waste of time!


You are wasting your time here Hawk....Obviously it is not so interesting for others as for you...
In last few months you can meet only autists persons here and lrl lovers...mostly people without elementar eletronic education, so you are wasting your time here.....

[Qiaozhi]

I had a lot of problems to extract it from .pdf and
put in useable .jpg.....

The easy way is to use the snapshot tool in the Acrobat toolbar.
Simply zoom in until you can see the text more clearly, then pan to the top left of the document. Select the snapshot tool, then hold down LH mouse button and drag it across the screen. The image should move to the left as you reach the edge of the screen. Once you have enclosed all the schematic, release the mouse button. The image will be pasted to the clipboard. You can then paste it into your favourite graphics package.
Here's the result below ->

[Qiaozhi]

Positive(VCC) is wired properly,but labeled as ..7905.???
Negative (VDD.....) is missing...

There may be other errors in this schematic. Who knows?
Perhaps someone here has built it.
You are correct that the -ve supply is not shown. Also it is incorrectly labelled as VDD instead of VEE.

[hawk17966]

Bravo !


Qiaozhi, bro'...you always shows here what a good spirit you are!
Because of You,Geo and very few others, i still grove a hope that this forum is not busted yet!
Thank you very much for tips and be good..
See ya more...
best regards

......
So now...my questions are still unaswered about CoinHawk...any .pcb???

Anybody tried it?
How come that so many people are interested in some depth detectors, while most "sweet" finds are actually in first 20cm in ground....So why asking so
much depth from devices....Why do not focus on good coinshooters?
Any pro here? I mean real pro?

[Qiaozhi]

If you want to try building this CoinHawk detector, I would say that it has a good chance of working. It looks like a fairly standard design for an IB detector. There are essentially two synchronously demodulated channels - all metal (resistive) and discriminate (reactive). You should be able to leave out the pinpoint channel, which would simplify things somewhat.
Of course, you'll also need a diode pump circuit to generate the negative supply.
This appears to be a fairly straightforward construction project, and even seems to be designed to work with a Tesoro concentric coil. Using the inductance values for this coil would give a TX frequency of 12.23KHz, with the receiver tuned to 13.31KHz, which sounds about right.
The reason I believe this is true is because the TX and RX coils share a common connection, which is a feature of Tesoro coils.
I also note that the wire-ORed output of U8A and U8B have a connection labelled "uP Trigger Drive". This detector will work without a microprocessor, and its only purpose must be to provide an LCD display giving phase-shift information. Once the uproc gets a trigger signal it can sample the X1 and X2 receive nodes and calculate the phase angle (or VDI number).
You should probably try building this on stripboard (Veroboard) first.
And yes - it is very interesting.

[hawk17966]

Many thanks!


Many thanks!
I'll try it in next month or two.....I have to draw pcb first, which is pain in the *** sometimes....
Later i'll post my experiences...
Thanks a lot bro'

[Qiaozhi]

Many thanks!
I'll try it in next month or two.....I have to draw pcb first, which is pain in the *** sometimes....
Later i'll post my experiences...
Thanks a lot bro'

Good - I look forward to seeing the results.

[Carl-NC]

There may be other errors in this schematic. Who knows?
Perhaps someone here has built it.
You are correct that the -ve supply is not shown. Also it is incorrectly labelled as VDD instead of VEE.

VDD (-5v) is generated by the LTC part (sorry, can't read the pn) on the far right, no doubt a voltage inverter. So the regs on the left are correct. However, I do question the audio driver... Q5 & R11.

- Carl

[Qiaozhi]

VDD (-5v) is generated by the LTC part (sorry, can't read the pn) on the far right, no doubt a voltage inverter. So the regs on the left are correct.
- Carl

What eagle eyes you have! I completely missed that.
My printed copy shows this device to be an LTC1044CP, which is a switched capacitor voltage converter.

However, I do question the audio driver... Q5 & R11.

I'll take a look at that.

[hawk17966]

Go Carl!


Go Carl! Go for more! Since i am amateur i wouldnt like to "die" drawing that pcb and later found out some more mistakes..If you have any more doubts please talk here, cose i am prepared in next month to start drawing pcb....Of course i 'll do that manually !??? Crazy, isnt it? But i am used to...
When finished i'll post everything here....
Thanks!

[Qiaozhi]

Go Carl! Go for more! Since i am amateur i wouldnt like to "die" drawing that pcb and later found out some more mistakes..If you have any more doubts please talk here, cose i am prepared in next month to start drawing pcb....Of course i 'll do that manually !??? Crazy, isnt it? But i am used to...
When finished i'll post everything here....
Thanks!

Why not use Eagle PCB? It's freeware and very easy to use.
http://www.cadsoft.de/freeware.htm

[okantex]

I offer expressPCB
even I am not EE or tecnition,I can use it.
free ,too.just you can not print out.you have to copy to paint then print it.

[Qiaozhi]

I offer expressPCB
even I am not EE or tecnition,I can use it.
free ,too.just you can not print out.you have to copy to paint then print it.

I also Express PCB, but Eagle is much better, and you can print out.

[Qiaozhi]

However, I do question the audio driver... Q5 & R11.

I'll take a look at that.

OK - I've taken a look at it, and (guess what?) Carl's correct. It doesn't work.
There appears to be a wiring error in the schematic. Try this instead:
Notice the rewiring of the transistors, plus removal of R11 and R6.
Does anyone know the origin of this CoinHawk schematic? The only reference I can find is here -> http://www.todoelectronica.com/Revis...as/Esquema.pdf