BARACUDA-Legend-1

[silverdog]

Hi all,

Excellent job , Bravo ....

I am looking for the day , it will be ready for production with all complete components .


Regards .

Do you mean you are waiting for a pre-built pcb ?

[TH Jim]

Hi Guys,

I'm just about to start work again on my Barracuda after a break, I'm interested to know what components you guys omitted from the pin point circuit? I seem to have trouble with the threshold being skewed and wonder if this is the reason?

Regards James.

[Morris_jo]

Hi all,

Excellent job , Bravo ....

I am looking for the day , it will be ready for production with all complete components .


Regards .

[Alexismex]

Hello friends , i have not test it but i think is for another function this
test point

[6666]

I have not tried the pin point on my Bara yet, maybe Alexismex can comment if his works ?

[ivconic]

..... I omitted the pinpoint circuit as it was causing problems with setting the threshold. It was holding the voltage at -5v on the LF412, pin 5 for some reason... probably just a bad component.

Don

Me too!? Strange.. i couldn't make it work. Sounding all the time...
So it is not bad component, maybe wrong component value?
Aside PP, my Barracuda is working SPLENDID!

[dfbowers]

Finished Baracuda from Silverdog this weekend. I will say Bravo! as well. Yes, a bit better than the Surf PI, longboard version from Silverdog. An easy extra inch with a 9" coil for coin sized objects over the Surf PI longboard. I'm seeing a pattern here with coil size and PI detectors. 9" is my personal preference.

Coil observations: I settled on a 9" coil with 28T, 22AWG 7 strand, silver teflon coated wire.
1e can be easily detected at 10-11".

Other coils tried: 8" coil of 300uH - 20AWG magnet wire - Very good! Detection range for coin size objects probably an inch less than with a 9" coil.

10" coil of 240uH 22AWG 7 Strand, silver teflon coated wire - Greater detection range on coins but at the expense of signal intensity.

Building notes: I omitted the pinpoint circuit as it was causing problems with setting the threshold. It was holding the voltage at -5v on the LF412, pin 5 for some reason... probably just a bad component.

Don

[bernte_one]

i use my coil if litz wire 490mH and 1,5R 23cm
1 euro is something up to 28-30cm
1kg of copper wire i got over 1meter

tested indoor

[ivconic]

Yes I tried the 230uH coil, it worked ok but I could see ringing
I hope to try and trim the damping resistor next week
Have you tried any dual field coils ?

Not yet...

[6666]

Yes I tried the 230uH coil, it worked ok but I could see ringing
I hope to try and trim the damping resistor next week
Have you tried any dual field coils ?

[ivconic]

Hi ivconic
glad to hear your Bara is working ok
I have tried a couple of different coils
but I also see a lot of ringing on the scope so I
need to trim the coil damping resistor
and give it a good tune
its a good project.

Have you tried inductances under 0.3mH?

[6666]

Hi ivconic
glad to hear your Bara is working ok
I have tried a couple of different coils
but I also see a lot of ringing on the scope so I
need to trim the coil damping resistor
and give it a good tune
its a good project.

[ivconic]

Also experiment with few more coils. Made one with 27 windings, different wire.. gave some ~0.4mH
Not so good as previous one.
Also have dozen spare coils with various specs. Tried some of those.
Seems this circuit operates much better with lower inductances!
Resistor is 330ohms/3W and i haven't changed it. It is cool all the time.
TIP is a bit hotter or a bit cooler - depends on a coil specs.
But performances are really good with coils under 0.3mH.

[ivconic]

Couple days ago i received Barracuda and Surfmaster pcb's from Silverdog.
First, must say, pcb's are SPLENDID! Bravo Silverdog! I am delighted with quality!
So i made Barracuda.
Haven't all fets from same specs, so i put one 2N5484 and three BF256's.
Haven't TIP127, so used TIP125 instead.
Instead 6800uF - 4700uF.
Coil is 19cm diameter, 24 turns of 0.5mm (haven't measured exactly...could be even 0.6mm) wire.
Resistance is 1.5 ohms and inductance ~0.25 mH.
It is working pretty descent!
Yes, seems is a bit better than Surfmaster!
Very sensitive on smallest coins.
Not sensitive on hotrock and minerals (when Delay adjusted properly).
1e coin can detect in air up to 25cm! Very good!
Larger items - more detecting distance... some up to 50cm!
Tip125 is getting a bit warm, not to much. Will survive even without heat sink.
Overall... i am satisfied.

[6666]

I just rechecked my silerdog kit, the resistors are mostly carbon i think, some are metal film
so I retract my previous statement, I will get some 270k's and test them and see how close they are, cheers