Gary Pulse 1 and change to a smaller resistance R17, the circuit is more sensitive?

[yhl]

Gary Pulse 1 and change to a smaller resistance R17, the circuit is more sensitive?

[yhl]

Looking for is building friends? Need to share learning

[yhl]

Gary pulse 1, is the worst of the circuit.

Gary pulse 1, is the worst of the circuit.

Is a garbage detector. Coins can only detect 5 cm

[Qiaozhi]

Gary pulse 1, is the worst of the circuit.

Is a garbage detector. Coins can only detect 5 cm

Not according to Gary, or several others who have made it. Either you have not built it correctly, or there is a fault ... or both.

You must get an oscilloscope if you want to continue building metal detector circuits, otherwise you're only making life difficult.

[RS_Phil]

I'm also getting bad result in gary's PI...i think the problem is the coil turn and number of the coil, hi Quaozhi any idea?

[Qiaozhi]

I'm also getting bad result in gary's PI...i think the problem is the coil turn and number of the coil, hi Quaozhi any idea?

You will need to supply more details.
What bad result are you getting, and what are the parameters of your coil?

[RS_Phil]

You will need to supply more details.
What bad result are you getting, and what are the parameters of your coil?

Sorry, I get bad result of depth detction, with 11 inches dia. of coil (wire #21 AWG i try 25 turns, 30 and 35) i only get 20 cm distance. and i have also second problem poor sound even in piezo speaker..

[Qiaozhi]

Sorry, I get bad result of depth detction, with 11 inches dia. of coil (wire #21 AWG i try 25 turns, 30 and 35) i only get 20 cm distance. and i have also second problem poor sound even in piezo speaker..

OK - but what is the size of the target you're using?

[RS_Phil]

OK - but what is the size of the target you're using?

coin 1 peso...

http://en.wikipedia.org/wiki/Philippine_one_peso_coin

1.00 Peso

6.1 g

24.00 mm

Milled

nickel-plated steel

[Qiaozhi]

If you bought a kit from Gary (Chemelec) then he will be pleased to assist you. If you didn't buy a kit, then you're on your own.
Gary gives some tips here ->
http://chemelec.com/Projects/Metal-1a/Metal.htm

[RS_Phil]

Yeah! i know that, thanks for advice, i was posting only about my gary PI problems maybe others can help who was experiencing the same problem and they solved it.

[Qiaozhi]

Have you read through the posts here -> Gary's Twin Coil PI in the Projects section of Geotech?

[chemelec]

Re: Qiaozhi, Previously I sent Saromines Ramiel a private message, giving him some advice.

Saromines Ramiel, A 20 Cm on that coin, Using an 11 inch coil is not that bad.
But What Distance did you expect?

An 8 inch coil (300 to 400uH) would be better for small objects, like coins and rings.
The 11 inch coil would be better for Larger objects, like pop cans and bigger stuff.

Also, some Peizo's are not very loud, Especially the small flat ones that are Not in a "Acoustic" Plastic case.
This is why I recommend getting the parts from me.
The "Projects Unlimited, AT-3045" Piezo that I supply has GOOD Volume.

Take care......Gary

[Qiaozhi]

Thanks Gary!