Metaldetector

[Smartsword]

Metal detector:
I have an urgent question!!
Like the video in the link:
The copper wire has two connections...But only PIN2 is shown in the video?!?

How i connect the two end of the wire?

 

[Smartsword]

OK.
What does everything on the circuit belong to DO?
can you draw that on the circuit?

 

[Smartsword]

I only want the circuit with an analog output and without LED. But the circuit still has to work. I just want to reduce everything. But the potentiometer has to be on it! What does everything on the circuit belong to the digital output?
can you draw that on the circuit?

 

[Smartsword]

I only want the circuit with an analog output and without LED. But the circuit still has to work. I just want to reduce everything. But the potentiometer has to be on it! What does everything on the circuit belong to the digital output?
can you draw that on the circuit?

 

[rjenkinsgb]

Everything to the right of VR1 is for the digital part, also R2 and R6.
The right part adds threshold detection and a massive amount of gain.

In other words, you would be left with the transistor, R3 and VR1. It will not do much and it is not a true analog output, as in, a varying voltage proportional to input signal.

As you have been told repeatedly, it's a "hum" detector. The AO output would be distorted audio; hum and noise.

 

[alec_t]

How i connect the two end of the wire?

You can ignore one end, or you can connect both ends to pin 2. The results will be indistinguishable.

 

[Smartsword]

It works with online analog but:

Is the r3 150R oder 150k?
The Signal from the darlington is too low! How can i get higher???

 

[Nigel Goodwin]

It works with online analog but:

Is the r3 150R oder 150k?
The Signal from the darlington is too low! How can i get higher???

It's clearly marked 150 ohms.

 

[Smartsword]

How can I amplify the signal more clearly?

 

[alec_t]

VR1 set to maximum will give the highest amplification.

 

[audioguru]

The LM393 IC on that module is a digital on-off comparator that picks up strong interference signals that are converted to on-off digital pulses that are not clear. The darlington transistor at the input has a minimum input voltage of about 1V that ignors all lower voltage levels, then amplification will not help increase the sensitivity.

 

[Smartsword]

I want to close a circuit across the floor like in the picture. like a switch to the ground. What kind of power source is needed? how can this be implemented? as simple as possible!! maybe with body touch sensor??

 

[Smartsword]

I want to close a circuit across the floor like in the picture. like a switch to the ground. What kind of power source is needed? how can this be implemented? as simple as possible!! maybe with body touch sensor??

 

[Smartsword]

my question is:
how can I detect contact with the ground? (not metal floor) is that even possible? and when then how?

 

[ZipZapOuch]

how can I detect contact with the ground?

Which ground?

 

[Smartsword]

Gym floors are usually made of plastic

 

[Smartsword]

Hi

Is it possible to detect the plastic floor of the gym in any way with two electrical contacts? about grounding

 

[alec_t]

What do you mean by "about grounding"?

 

[stubbzord]

I would personally go for a PI (Pulse injection) type detector as they are much more reliable. Member Chemelec here had a design on his webpage but unfortunately dies a few years ago.

 

[ZipZapOuch]

Hi

Is it possible to detect the plastic floor of the gym in any way with two electrical contacts? about grounding

No.