DELTA PULSE / SNIFFER XR71 PULSE INDUCTION METAL DETECTOR

hello hesamavr ;
thanks for informations and good luk with your circuit.......
hai Logenxx ;
good idea for builing the coil , and d'ont forget to helping when you modifie the circuit for more power..............good luk and sorry for my bad englech
Regards...........raff

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hello hesamavr,
- with 45cm diameter it detect a canet PEPSI(250ml) at 70cm ; a coin (3cm) at 28cm ; iron plat 40cm*25cm at 140cm ;but i remarque that DP has poor detection for gold..... a coin (2.5cm) at 18cm.
- with 1m*1m coil it detect a canet PEPSI(250ml) at 110cm ; iron plat 40cm*25cm at 2m no more , i test with  iron plat 1m*60cm the same result    i don't now where is the probleme.........

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hello Masons21!
maybe your search coil has no faraday shield. put your coil a little bit away, @3" to 4" away from ground.

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		Quote:			Posted by hesamavr
	Dear Raf33 I propose that you increase the turns of your coil and see what happens, if you want. but the friends who reached higher depths, don't help us in this situation.

This is precisely why people get discouraged from building a project. You can't just change a design parameter and expect your project to perform in any way but less that the design specification. There is no room for twiddling with electronic components. The idea is to match the specification exactly, not to be clever and see what happens.

In a few days time, we will see a message here about how this or that isn't working right. After a bazillion questions, we get to the bottom of the problem and find out that the design has been modified by someone who took the advice of the postman when he delivered the mail.

If you are not a qualified design engineer, please refrain from giving advice like this. Changing the coil will cause the design to be unstable at best or not work at all. Either way, your comment here will be the reason that a moderator or design engineer will have to sort things out. Worse yet, your suggestion becomes a permanent part of the thread making it seem a good idea for months and months when it will, not might, make the project malfunction.

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		Quote:			Posted by hesamavr
	if you are qualified engineer, help him and say what's his problem. your qualified engineers in this forum mentioned that the coil resistance could be between 3..4Ohm. his coil has 3Ohm resistance, this is the reason why I said this based on GOOD posts suggestions (page 18, First post by Eugene51). you can delete all of them if they are wrong. if you have any interesting information, share it with us. these forum is full of unused post, you didn't see them but you only see my "suggestion" here and you humiliate me with such words. I constructed this circuit and I know what he mentions, I have his problem also but as I said in previous post, the engineers who reached higher depth don't help us.

Mate, it's been shared at least a dozen times and gets ignored each time. For what will not be the last time you MUST understand that the resistance is a RESULT of a coil that is wound with the proper IMPEDANCE and not something you design into the coil. You do NOT wind a coil to match the resistance of another coil. You wind a coil to match the IMPEDANCE and if the RESISTANCE is not a match, it does not matter. The resistance could possibly diminish the current in the circuit but it will not affect tuning.

If you wind a coil with the idea that matching the resistance is the goal, it is a guarantee that you WILL not get the correct impedance and the circuit will be detuned. Detuning means that you will never get a response that is recognized by the receiver.

Basically, do not twiddle with the circuit. Period. End of story.

An engineer, like myself, wouldn't EVER do it to a working design. Why would I advise YOU or anyone else to do it?

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