DIY pulse metal detector.Finds a coin at a distance of 20cm

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Күн бұрын

Пікірлер: 30

@Kositsyn83 Жыл бұрын

If your metal detector is not working well. The resistor parallel to the coil MUST have a resistance of approximately 330 Ohms, you can change it to a few tens of Ohms and check whether it works worse or better. The 1000 uF capacitor that is on the supply, it is better to place it closer to the terminals supply TL072, and the other at 470 uF is closer to the terminals of the generator coil.These are the two main reasons why the device will not work well. This should be done if there is a constant buzz or something else when you turn on the power.

@szescioscian Жыл бұрын

I built it and it doesnt work. I mean that I made a mistake somewhere but I dont know where. My detector works only on for example my laptop but when the laptop is turn on. It means that it detects only things which are powered by electricity. Can you tell me where I have a mistake?

@kn-qz7by 5 ай бұрын

Can you build a PI detector that penetrates MUCH deeper than only 20 centimeters (7.87 inches)? Even a VLF detector can easily find a coin at that shallow depth. If so, THAT would be impressive!

@louisudin4159 Жыл бұрын

I have a lot of questions about this. Where did you connect the function generator and what is the input? Where did you connect the coil? Please help me ASAP

@mazensued164 2 жыл бұрын

Please explain why the windings are chosen with a specific number and how the parallel resistance of the coil is chosen

@hpktech7736 Жыл бұрын

sound same. how to change sound indifferent types of metals

@shadiabuaalim8190 Жыл бұрын

Bro...about filter DC what must do

@shadiabuaalim8190 Жыл бұрын

I need asked you if amp important for this circuit .. 12v ..300ma it's good or not

@spikezzX Жыл бұрын

@shadiabuaalim8190 Жыл бұрын

Bro ic 555 only out put 139,hz

@elarcadenoah9000 Жыл бұрын

where is the diagran esquematic?

@rezatavan5048 Ай бұрын

Excellent

@ulquerhaawaken Жыл бұрын

In the figure, at the leftmost down part is it 0.1 farad capacitor

@DickDavidse 9 ай бұрын

Hi Artem, The current running thru the IRF740 is approx 1 amp. Is that correct?

@Kositsyn83 9 ай бұрын

in a pulse it is quite possible, but the direct current consumed by the metal detector is about 30mA

@DickDavidse 9 ай бұрын

@@Kositsyn83 Thanks for your reply. Without any dection or pulse, the current still is approx 1 amp. My oscillopscope shows a neat pulse on the IRF gate. Without the coil connected I also see a nice pulse on the 220Ohm resistor. The coil is 20cm in diameter and has 30 turns (0.5 mm) giving a resistance of 2.6 ohms. Maybe thes figures helps to explain what is going wrong.

@conto7032 2 жыл бұрын

Can you please specify inductance of coils or gauge of wire used ? I have problem with receiving response. I can see same 100V spike on my oscilloscope, however when i place something like swissknife on it nothing changed. I tested with coils 2.5 mH, 200 uh (SWG19) and 4mH (SWG40). R1 and R2 values so i got different frequencies. Do you have some data-set for R7 values to change of response time. (I used 300 instead of 330)

@Kositsyn83 2 жыл бұрын

your coil is wound correctly. R7 must be about 330 ohms. Change the generator frequency C1.

@conto7032 2 жыл бұрын

@@Kositsyn83 Thanks for fast response, I will try mentioned changes. My coil (2.5 mh ) is wound around plastic cylinder. No special winding. (Was used in different type of detector as TX coil. I just wanted to try it in pulse detector.) Is there need for special winding ? If so can you refer to it by name so I can find it on google ?

@conto7032 2 жыл бұрын

@@Kositsyn83 OK, I tried some changes and i did figured it out. I used 100K potentiometer as R1 and R2. Then 2x 1K potentiometers on R7 and R8. By trial and error I found way to see best ratios for each coil. My initial problems were coil didn't recovered fully after reset and pulse was too short.