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Metal Detector

Start with the video, then use the science notes and recommended parts below to follow the idea behind the build.

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How it works

What this project is testing.

A metal detector uses a changing magnetic field to ask, is there a conductor nearby? Metal answers by forming tiny circulating currents inside itself.

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This project demonstrates induction: those eddy currents create their own magnetic field, which slightly changes the detector tone or signal.

E = - \frac{d Φ _{B}}{d t}

Changing magnetic flux induces voltage, which is what drives eddy currents in nearby metal.

f_{0} = \frac{1}{2 π L C}

Many simple detectors listen for small shifts in a resonant oscillator.

Recommended parts

Products used in this project.

Affiliate links may earn Keystone Science a commission. Match ratings, values, sizes, polarity, and safety requirements to your own build before buying.

Jesverty DC Power Supply Variable, 0-30V 0-10A Adjustable Switching DC Regulated Bench Power Supply with High Precision 4-Dig

bench DC power supplypower

Variable DC Bench Power Supply, 30V 10A Adjustable Regulated Supply

$64.994.5(2,700)

Amazon Basics 8-Pack 9V Long-Lasting Alkaline Batteries for Smoke Detector, Electronics & Audio, Reliable, 5-Year Shelf Life

batterypower

Amazon Basics 8-Pack 9V Long-Lasting Alkaline Batteries

$12.694.7(242K)

General electronics battery pick; choose AA/AAA variants when the circuit calls for them.

Rigol Digital Oscilloscope DS1054Z 50 MHz 4-Ch 1 GSa/s 24 Mpts 30,000 wfms/s UltraVision 7" 800x480 Intensity Display, 60,000-Frame Record/Playback, Serial Decode UART I2C SPI for Debug & Education

oscilloscopetest equipment

Rigol DS1054Z Digital Oscilloscope, 50 MHz, 4 Channel, 1 GSa/s

$349.004.7(724)

Good bench choice; budget scope alternatives may be cheaper but less durable.

EDGELEC 120pcs Breadboard Jumper Wires 20cm Wire Length Optional Dupont Cable Assorted Kit Male to Female Multicolored Ribbon Cables

jumper wires / hookup wirewiring

120pcs Breadboard Jumper Wires, 20cm Dupont Cable Assorted Kit, Male to Female

$6.984.7(4,500)

BNTECHGO 30 AWG Magnet Wire - Enameled Copper Wire - Enameled Magnet Winding Wire - 4 oz - 0.0098" Diameter 1 Spool Coil Natu

magnet wirewiring

BNTECHGO 30 AWG Magnet Wire, Enameled Copper Winding Wire, 4 oz Spool

$12.984.6(387)

TUOFENG 30 awg Wire Solid Core Hookup Wires-6 Different Colored Jumper Wire 100ft or 30m Each, 30 Gauge Tinned Copper Wire PV

copper wirewiring

TUOFENG 20 AWG Solid Core Hookup Wire Kit, 6 Colors

4.6(1,700)

BOJACK 1000 Pcs 25 Values Resistor Kit 1 Ohm-1M Ohm with 5% 1/4W Carbon Film Resistors Assortment

resistorpassive electronics

BOJACK 1000 Pcs 25-Value 1/4W Carbon Film Resistor Assortment Kit, 1 ohm-1M ohm

$9.994.7(4,500)

BOJACK 24Value 630pcs Aluminum Electrolytic Capacitor Assortment Box Kit Range 0.1uF－1000uF

capacitorpassive electronics

BOJACK 24-Value 630pcs Aluminum Electrolytic Capacitor Assortment Box Kit, 0.1uF-1000uF

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BOJACK 12 Values 120 Pcs Opamp Timer Darlington Phototcoupler LM324 LM339 ULN2003AN ULN2803APG LM358P LM386 LM393 NE5532P NE555P UA741CN JRC4558D PC817 IC Assortment Kit

integrated circuit / ICsemiconductor

BOJACK 12 Values 120 Pcs Opamp Timer Darlington Phototcoupler LM324 LM339 ULN2003AN ULN2803APG LM358P LM386 LM393 NE5532P NE555P UA741CN JRC4558D PC817 IC Assortment Kit

$18.994.8(511)

BOJACK 20 Values 200 Pcs Inductor 10 uH to 10 mH 1 W Color Ring Inductor 1 Watt Assortment Kit

inductor / coilpassive electronics

20 Values 200 Pcs Inductor Assortment Kit, 1uH to 4.7mH, 0.5W Color Ring Inductors

$13.994.8(182)

12V 2A Power Supply, AC 120V to DC12V 5.5x2.1mm Jack Converter, 12 Volt LED Driver 24W Adapter Transformer for Strip Lights, Surveillance Cameras, External HDD, Monitor, CCTV (Pack of 1)

transformerpower

12V 2A Power Supply, AC 120V to DC12V 5.5x2.1mm Adapter Transformer

$8.994.5(6,601)

General low-voltage transformer/adapter pick; match voltage/current and connector to the circuit.

CQRobot Speaker 3 Watt 8 Ohm Compatible with Arduino Motherboard, JST-PH2.0 Interface. It is Ideal for a Variety of Small Electronic Projects.

speakeraudio

CQRobot 3 Watt 8 Ohm Speaker for Arduino and Small Electronics Projects

$7.994.5(457)

TOSHIBA EM131A5C-BS Countertop Microwave Ovens 1.2 Cu Ft, 12.4" Removable Turntable Smart Humidity Sensor 12 Auto Menus Mute Function ECO Mode Easy Clean Interior Black Color 1000W

microwave ovensalvage

Toshiba EM131A5C-BS Countertop Microwave Oven, 1.2 Cu Ft, 1000W

$148.994.4(32K)

Recommend only as an appliance; do not encourage buying a working microwave for disassembly. Review requirements and safety guidance before buying.

BOJACK 10 Values 250 Pcs A1015 BC327 BC337 C1815 S8050 S8550 2N2222 2N2907 2N3904 2N3906 PNP NPN Power General Purpose Transistors Assortment Kit

transistor / MOSFETsemiconductor

BOJACK 10-Value 250 Pcs PNP/NPN General Purpose Transistor Assortment Kit

$8.994.7(763)

BOJACK 3 Values 130 Pcs Solderless Breadboard 4 Pcs 830 Tie Points & 400 Tie Points & 126 Pcs Flexible Breadboard Jumper Wires

breadboardprototyping

BOJACK Solderless Breadboard Kit with 830/400 Tie-Point Boards and Flexible Jumper Wires

$9.994.4(692)

Sand Paper, 48 PCS Sandpaper, 120 to 5000 Assorted Grit Sandpaper Sheets, 9 x 3.6 Inch Premium Wet Dry Sandpaper for Wood Fur

sandpaperfabrication

Fandeli Assorted Grit Sandpaper Sheets

$12.99

Project files

Prints, kits, and downloads.

Diagrams, printable files, kits, or companion downloads will appear here when they are ready to use.

Coming soon

Contact

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