make a metal detector

by:Kenwei      2019-09-08
Hello everyone! !
Today, I want to show you a simple way to make metal detectors.
Can you find gold hidden underground with this metal detector? Answer is NO.
Do not expect this metal detector to work like a commercial metal detector.
You can make metal detectors with complex circuits to do the job perfectly.
However, this is not the focus of this version, in fact, the main purpose of this version is to familiarize yourself with the basics of simple electronic products.
It\'s just a warning because a lot of people expect too much from me and won\'t be too disappointed with anything I do or show.
In addition, I am a Grade 11 student, not a graduate of electronics, so I will definitely make mistakes. If you help me correct them, I will be very happy.
Anyway, let\'s move on now that a warning has been raised.
The circuit was built on instructions provided by a YouTubers called Ludic Science.
Please visit him for more information or more interesting lines.
Instructable is divided into many steps to ensure that it is very simple to follow these steps.
Steps are divided in the following order: 1)
Step 1: Watch the video! 2)
Step 2: Circuit Schematic diagram and breadboard diagram. 3)Step 3-
9. Make a circuit on the bread board. 4)Step 11-
16: make the circuit on the perf board. 5)
Step 17: How does it work? 6)
Steps 18 and 19: trouble shooting skills and sorting out words.
Okay, let\'s build it! !
Most of the content in the video is included in this manual, but if you like to watch the video instead of reading the manual, then watch my video!
I really hope it will help you in some way.
Watching videos on youtube will also increase my youtube views and maybe increase my funding for future projects, so give it a try!
This is the schematic diagram of the circuit and the breadboard diagram.
I hope this helps a lot with the making of the circuit because it is difficult to indicate the connection position of the wire separately.
So, try following the schematic and breadboard diagrams if you can.
Normally, the circuit we are trying to create ends up not working, so it is recommended to create any circuit on the breadboard before soldering to The perf board.
To make it on a breadboard, you need to: 1)
555 timer IC chip. 2)
2X1 uF electrolytic capacitor. 3)
1X10 uF electrolytic capacitor. 4)47 KΩ Resistor. 5)A speaker 6)
9V battery and clip 7)Breadboard 8)
28 gw wire and cylinder with diameter of 1 inch.
Take the cylinder, coil line 220-
Around 250 times.
Make sure there are about 2 inch wires left on both ends of the coil. (
If it is confusing, I will describe it in detail later. )9)
Jumper and crocodile clip.
You also need a lot of patience to wrap the wires without messing around.
Take the bread plate first.
As shown in the figure, place the IC chip in the middle of the board.
Make sure the cut on the IC is facing the left side.
When the gap of the IC is left-facing, then the pins from left to right are 1,2, 3,4, and the pins from right to left are 5,6, 7,8.
Reference picture for Pinout.
Connect the pins 4 and 8 of the IC using jumpers.
Connect the pins 2 and 6 of the IC using jumpers.
Connect the 1 uF electrolytic capacitor to the ground and pin 2 of the IC.
Connect the pin 1 of the IC to ground using a jumper.
Connect the side of the 10 uF electrolytic capacitor to pin 3 of the IC.
Connect the speakers to the ground end and negative end of the 10 uF capacitor we just connected.
Connect the pin 4 of the IC to the positive power rail using a jumper.
Connect the 47K ohm resistor to pin 6 of the IC.
Connect the jumper of the IC pin 3 to the other end of the 47K ohm resistor.
Connect the 1 uF electrolytic capacitor to pin 6 of the IC.
Connect the battery clamp lead to the breadboard power rail (
Two rows of long dragons on the side. )
So now we have to do the most important part of the circuit, that is, the part that detects the metal.
Take a cylindrical plastic bottle with a diameter of 1 inch.
It is very important that cylindrical objects are plastic or non-metallic and hollow things.
Get some magnet wires.
The magnet line is just plain copper wire with a thin layer of porcelain glaze insulation.
Leave a 2 inch wire at the end and tape the wire to the bottle.
Now start wrapping wires around the bottle 220250 times.
Try to make the coil clean and tidy.
Then tape the end of the coil to the bottle so you can leave another 2 inch of the wire at the end.
So now you have a circle of wires around the bottle and the end of the coil is 2 inch long.
Now take a pair of scissors and scrape off the insulation from the end of the wire.
This step is very important.
You can also burn it with a lighter if you want.
If this step is skipped, the wire will not be in contact with the crocodile clip and the circuit will not work.
Now connect the crocodile clip from the wire to the end of the 47 K resistor and the 1 uF electrolytic capacitor.
The circuit is done! !
Connect a 9 volt battery to the battery clip.
The circuit should produce a nasty treble noise.
Now bring a metal in the bottle with a coil, such as scissors or pliers, the tone of the sound should change, indicating that you have metal in your bottle!
If you take your finger or any other dense non-metallic object, the tone of the noise will not change.
It only changes when the metal is close to it.
Congrats!
You\'re half done!
Now is the time to make it permanent! ! !
You need the following to make the circuit permanent: 1)
555 timer IC chip.
2)
2X1 uF electrolytic capacitor. 3)
1X10 uF electrolytic capacitor. 4)47 KΩ Resistor.
5)
A speaker
9V battery and Clip7)28 AWG Wire. 8)Perfboard. 9)Switch10)
A cylindrical object with a diameter of 1. 5 inches. 11)
8-pin IC socket. (
Welding IC will damage IC due to high temperature.
So we will weld the socket and insert the IC into the socket later. )
We will make the inductor again.
You can use the inductor from last time if you want, but I decided to change it.
I decided to make the coil more flat and larger in diameter, so now you can detect the metal by simply hovering the coil over the metal.
So take the plastic cylindrical object, tie the wire to the cylinder, and finally leave the 2 inch wire, then start winding around the plastic cylinder 150 times.
Leave 2 inch of the wire at the end and put the wire tape in place again.
Use a lighter or scissors to remove the insulation from the end of the wire.
Place the IC socket in the middle of the perf board.
Imagine that it was the previous IC chip and put the components on the breadboard as before.
Please refer to the schematic to create the circuit again.
The circuit images I provide can be misleading in stages because a lot of the connections I do are done while welding, not by placing wires and jumpers.
So refer to the schematic as much as possible.
Weld the connection you have created so far.
Pay attention to safety when welding.
Now, connect two long lines on the board and weld them to the switch.
Connect two more wires and weld them from the coil to the wire.
Your circuit is done!
After completing the welding, insert the 555 timer IC into the socket.
Now cover the leads and welded joints with hot glue or tape to reduce the possibility of short circuit.
Select what you want to place the circuit.
I chose a craft because it was the easiest I could find.
But you should be more creative than I am and at least respect your efforts to create this track.
And connect the battery to the clip.
Now use rubber bands, hot glue and anything in your home to organize the circuit in a decent way, making sure there is no metal near the coil when you connect to the base.
We\'re done! ! !
Just press the switch and it will turn on the annoying high tone sound and bring metal around and you will hear the tone change of the noise.
Congrats!
But don\'t worry if it doesn\'t work, I have some trouble shooting tips for you.
I am not an expert and I am not qualified to explain how it works.
But if you start learning about electronics like me, I can communicate the basic concepts to you.
If you find any errors in my explanation, please correct them for me.
Inductor: the inductor is just a bunch of wires to resist any change in current.
The inductance of the inductor depends on the diameter of the coil, the number of coils, the height and width of the coil, and the material inside the coil (
Hollow air or metal rods. ).
If any of the above factors are changed, the inductance will change.
The 555 timer chip can do a lot of things, but the most common one is to generate clock signals.
The pin 3 of the IC is the output pin.
It can output high and low voltage.
Sound is generated when the output of pin 3 changes very quickly from high to low.
The change speed of the output from high to low is the cause of the noise tone.
If the output changes slowly, the Speaker will have a bass high noise, and if the output changes quickly, the speaker will produce a treble high noise.
Pins 2 and 6 are connected to two comparators inside.
What the comparator does is compare the input voltage to the output high or low.
The output of pins 2 and 6 then determines the output of pins 3.
The wiring of two 1 uf capacitors and resistors and the inductor makes the input voltage of pins 2 and 6 constant, if the input voltage of pins 2 and 6 constant, their output will change, and the output of pin 3 will change.
Like a chain of reactions.
If the value of any resistor, 1 uF capacitor or inductor is changed, the output frequency of pin 3 will change.
In our case, the value of the capacitance and resistance remains the same.
However, the value of the inductor can be changed.
When we close the metal to the coil, the inductance of the coil increases.
The change in inductance in turn leads to a series of other events that need to be explained by professionals.
But anyway, when the inductance changes, the final result is a change in the spacing of the noise.
Higher inductance on the coil = lower pitch noise.
Lower inductance on the coil = higher pitch noise.
This is probably the worst explanation you \'ve ever read about circuit functionality, but this is the best explanation I can do before confusing you or even myself.
So in the next few paragraphs, I will try to solve some of the problems you may face when making.
Question 1: my circuit is useless to you as a liar!
Your life is a lie!
Solution: calm down because I have neither the patience nor the sadist nature to let others waste their young time making fake circuits.
Let\'s slow down and handle the rest. (
This happened countless times on youtube and people accused me of not working on the circuit. )
Question 2: The circuit is broken. Can you fix it for me?
I can\'t even hear the sound.
Solution: Now this is a better way to express your opinions and needs.
OK, the circuit may not work for a few reasons.
Is your connection correct according to the schematic? Check it.
If the connection is correct, please check if you have made the welding Bridge. (
Accidentally connect multiple connections by welding overflow).
Is the capacitor with the right polarity inserted?
Check the continuity of each capacitor with a multimeter, if there is continuity between the poles of one of the capacitors, the capacitor needs to be replaced because the capacitor fails when the disconnection voltage is reached.
Did you remove the insulation correctly from the end of the coil?
Because a lot of times people don\'t do that, and the magic is that their circuits don\'t work.
Did you insert the chip in the right direction?
If you use a breadboard chart to build the gap, check to make sure the gap is facing to the left.
Try to change the speaker if you want.
Question 3: my circuit makes noise, but the spacing does not change when I close the metal to the coil!
Check the connection to the inductor.
Are you making it too small? ?
Try changing the size and number of loops of the coil.
Question 4: my circuit works and also changes the pitch when the metal is close.
But after using it for a while, the speaker creates a very high, grumpy tone noise!
Solution: there is a problem with the capacitor.
Close the circuit, hold the metal with pliers and use it to connect both ends of the capacitor.
It should discharge the capacitor.
Let the capacitor cool a bit and it should be ready to use again.
If this happens frequently, change the capacitance of the capacitor.
Question 5: my circuit changes pitch without needing anything!
Solution: may the Lord be on your side and help you through difficult times. Amen.
I hope you guys find this circuit interesting and maybe want to try to recreate it as well.
If that\'s the case, then it\'s a success for me to write this structure.
Once again, I am an amateur in the electronics industry, and I will definitely make mistakes.
I would appreciate it if someone helped me correct my mistakes.
If you can, help me with the explanation of how this circuit works.
Thank you for reading. I hope you will have a good time!
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