Vibration-Circuit for Metal-Detectors

[Funfinder]

After tough negotiations *laugh* I can proudly present you
my MD-Vibrator invention as schematic here at this forum !

It has been tested meanwhile under real search conditions
and it works great! I used the Garrett Euro-Ace for the test
and I even found small stuff (lead-bullet, 13mm, 10cm deep).

So far tested:
working:
Garrett, Fisher, Makro Jeohunter & Racer
not working:
DeepHunter (always signal), Blisstool (signals too fainting)


Of course now it's your turn to improve this thing if you like!
Or input some ideas for a dongle so other MDs will work, too.

I also think its not the best idea that the full current runs totally
through the vibration motor. I guess its better if theres an extra
division for the motor incl. variable resistor for vibration-strength.

And, for best results, use this MD-Vibrator with pulse induction -
or non-motion detectors, where a clear on-off signal is available!
Or - if possible - use pinpointing-mode to catch the weak signals.

Have fun!

[Funfinder]

After testing I found out that the vibration motor is a little bit weak
so the R3 47 Ohm resistor can be lowered to 22 or removed at all.

[MartyJ1963]

Hiya Funfinder,,,Will this 'Vibrator' circuit with the homemade DIY detectors on the forum,,IE:-surf/barracuda/minipulse/idx/igsl/tgsl/mirage etc,,,? Thanks,,,Marty

[MartyJ1963]

Hiya Funfinder,,,,Can you tell me if I've drawn the circuit correctly please? Thanks,,,,Marty

[Funfinder]

Welcome to the fantasy err fantastic world of pure vibration detection! :-)

Sure I can check it out, this is an interesting little puzzle game for me - when I have the time.
btw. my last puzzle game was MouseCraft on the Playstation 4. This game is so super cool,
I've even created my own levels.

Anyway - thanks that you've made this printable PCB version!

Concerning the housing it would be good if its metal to ground because of the
real high sensitivity and with some tough clamps screwed on, which afterwards
you can easily attach to the MDs stem etc. But strong plastic also works
because of the variable resistor which is there to lower the sensitivity.

[Funfinder]

Crazy coincidence, I saw the name Rotherham not long ago for the very first time.

> Hiya Funfinder,,,Will this 'Vibrator' circuit with the homemade DIY detectors on the forum,,IE:-surf/barracuda/minipulse/idx/igsl/tgsl/mirage etc,,,? Thanks,,,Marty

I don't know but I guess the chances are pretty good and you might be able to test it soon. Please tell us the results.


Here's the corrected layout, enjoy.

[MartyJ1963]

Thanks Funfinder,,,,,I'll have a go at building it for my sisters detector,,she's totally deaf so she may benefit from this. Regards,,,Marty

[Funfinder]

Thats a blessing-worthy motivation you have and great that you found the new layout that fast.
I wish her good luck - often such people have the best and craziest luck in treasure-hunting ever,
like this also some problems having guy in Swizzerland which found those huge gold-ore-stones.


You can try different diodes - also cheap Shottky ones - but I guess the category I have
choosen (1n914 or similar) works the best (glass diodes).

[Funfinder]

Parts List

- the above posted PCB: Vibration circuit pcb ok.jpg

(but you can solder the parts also directly together as I did if you have
enough imagination or if you can draw yourself a little sketch on paper)

- the vibration motor should be a little bit better and stronger as those ones
which are used inside of Smartphones but you can also use them, they are
just a little bit weaker (you can rip them from some old phone and try).
Polarity does matter if you attach them because those are DC voltage.
This means that you should connect the black cable into minus and
the red cable into plus direction - seen from the power source.

Apropos power: 2x 3,7v LiPo Batteries also should work.
If you know how the balance recharging works correctly.
You even can use some Digicam or Camcorder accu (7,4v)
if you can create or find any connectors-adapter.
The simple solution is a 9v LiPo rechargeable block, some old
NiMH 9v Block (but is more weak) or the usual batteries.

S 1: as switch you can use anything, even 2 wires bend together. *laugh*
If you wanna remove all the time the battery you even don't need any.
Of course the switch if in usage should be reachable from the outside.

VR 1: Variable resistor aka potentiometer: 200k.
I have placed it into the battery-compartment so its waterproof
and I must not adjust it all the time, anyway.
But you also can make it easy adjustable from the outside.

R 1: usual consumer electronics resistors: 470k yellow-violet-yellow-gold
R 2: 360k orange-blue-yellow-gold
R 3: 22ohms red-red-gold or replaced with wire for stronger vibration

D 1: diode 1n914 (or similar glass diodes, not too tiny)

Q 1: transistor BC548 (or with similar npn specs)

IC 1: integrated circuit ("intelligent chip") LM358
This is the OP-amp and comparing part.

Audio Left - Audio Ground:
this is simple mono audio where "left" stand for the
complete output. Because MDs so far have no stereo output,
they only provide the mono signal same for left and right.
This means you also can use some stereo-jack if available
and you just connect left and right as single left output.

The best here is to cut off the cable from a DJ-headphone
because the small wires inside are very resistant against
movements, shaking, breaking etc. For soldering hold
the wires a short time over a flame for burning the
isolation-coating and afterwards rub it away.
Ground is the shielding which either encloses the white (left)
or right (red) cables or its the non-colored gold-copper wire.


And last but not least:
Wearing the vibrator inside the trousers- or shirt-pockets
might be a good idea as long as you can feel the vibes
clear and strong enough. Otherwise its better if you
clamp, tape etc. the device near the MDs handle.

[Funfinder]

R 3: 22ohms red-red-gold or replaced with wire for stronger vibration
(or: red-red-black-gold)

[6666]

Thanks for this, I have a deaf friend who may be able to use this for gpx 5000

[Funfinder]

Thanx - the perhaps simplier solution is to buy some (used) Racer, Kruzer, Impact etc.
But I also will use this device for special MDs which have no vibration as default.
And your friend can hear with it also the higher pulses and frequencies of music
(and not just bass-vibrations) because the motor acts like a mini-loudspeaker-coil.
Death err deaf people also can connect this vibration circuit with their TV-audio-out.
This might feel then for them like the vibrations from gaming-console-controllers
and provides a somehow more realistic illusional feeling of whats actual happening.

[Funfinder]

Any progress so far?

[Funfinder]

Improved External Metal-Detector Vibration Circuit Version 2020

update log:

_ full power vibration strenght (resistor R3 removed)
_ no more disturbing detection signals caused by electrostatic charges
_ clear vibration control for MDs with single or dual audio output (Jeohunter, DeepHunter)
_ supports additional ( or even all ?! ) detectors now
_ schematic & PCB updated





Well, this was a lucky hit today - - while tinkering and probing around! *laugh*
Later I saw that the magic was done by shortcutting the variable resistor, but this part
now works even better than before. Guess it has to do with the weak audio AC input.
For the Garrett detectors it also works perfect now, even with lowered audio volume.
I can't test every single MD but the improved version now even works great with
the DeepHunter at motion mode 2, so I guess it will work with pretty any MD!


If you built this device make sure that the 200k variable resistor is good reachable
because depending on the used detector you have to adjust it for best performance.
And better attach a good and thicker audio-cable as connection which doesn't breaks.

[Maker]

This is just my "hello, world" message as a new member to be able to look at the circuit diagrams - please ignore. (Hopefully it's ok to put it here...)