metal detector kit
In the food industry, metal detectors are used to detect foreign metals and mechanical parts in food.
In terms of security, they are used to detect weapons.
In production equipment, parts are used for location detection and counting.
You can even use them for game entertainment or proximity switches on toy trains.
This is a kit I came up and down from Ebay just for the fun of building.
I found some results interesting while testing it.
Operating voltage DC 3-metal detector
5 v operating current 40 ma standby current 5 ma detection distance 60m malarm mode sound/light difficulty EasyPCB size 86*61mm circuit board purse weld iron needle nose PlyersSide side
Report on final accounts of metal film resistance 470ohm R3.
Resistance of metal film R2 2k 1.
Metal film resistor R1 200K 1.
Potentiometer VR1 100R 2.
Ceramic Capacitor C2, C3 0. 022uf 2.
Ceramic capacitors C1, C4 0. 1uf 1.
Electrolytic Capacitor C5 100uf 1.
Red LED 1 5mm 1.
Q1 to-S901892 1.
Power switch SW1 6*5mm 1.
The buzzer sp9 * 12mm 1.
Power socket J1 KF301-2P 1.
The power switch is missing in the 60 kit, but since I have a compatible power switch in my store, it doesn\'t slow me down.
There is no battery pack for this kit;
Since this metal detector operates at a voltage of 3 to 5 V, I recommend you to use 3 battery cases, so if you use 1 battery case.
2 V rechargeable battery for 3. 6 volts, or 1.
5 V 4 alkaline batteries.
5 Volt gives you the voltage you need.
While the elements are placed on the printed circuit board clearly and there is no assembly instructions, I just designed a schematic diagram in reverse for those who like them.
I like to check my parts first with the component tester, it is useless to assemble the circuit board with parts that don\'t work.
I start from one side and fix the part in the proper position with spring tweezers.
Then I weld the components in place.
This printed circuit board is small;
Therefore, if there is excess lead, reduce the excess lead before entering the next part.
This will prevent the lead of the previous part from interfering with the welding of the next part.
Continue testing and connecting components before assembling the board.
Remove the label on the surface of the buzzer and attach the battery holder.
Make sure you are not near the metal;
Open metal detector, LED ,(Red Arrow)
And buzzer ,(Blue Arrow)
Can come or not.
Adjust the 100 pot if the LED and buzzer do light up ,(Yellow Arrow)
Enough to turn them off.
If the LED and buzzer are not on;
Adjust the 100 pot until the LED and buzzer light up and then adjust the pot in another way to turn them off.
The LED and buzzer should be on at the same time.
This metal detector is weak,
However, I tested the detector on various metals and other objects, and these are the results.
Gold, detector weak response silver, detector weak response copper, detector strong response copper, detector weak response copper, detector strong response steel, detector strong response iron detector weak response magnet, detector weak response magnet, detector no response magnet, detector weak response magnetic core, detector no response transformer core, detector no response graphite mold, detector has strong response. Strangely, I think I will get a stronger response from the magnet because the magnetic field will affect the pick-up coil.
I also expect a stronger response from a powdered core such as a ring or transformer core.
The most important thing is that the graphite mold has a strong reaction, there is no metal inside.