Darcy Neal

The EMF Explorer Kit

Featured in Make: Volume 90!

$29.99 Sold Out
Shipping calculated at checkout.

Suggested Add-ons

The EMF Explorer Badge is an electromagnetic frequency sensing circuit that lets you listen to the world of hidden electromagnetic frequencies all around you!

So much can be discovered through listening. The way that Bluetooth hardware sounds when it’s operating. How cellphones sound when they are transmitting data. What a laptop touchpad sounds like when it detects touch. The electronics world is invisibly emitting sounds around us all the time that we are mostly unaware of.

The beautifully detailed art on the completed PCB can also be worn as a badge on a lanyard, used to illuminate yourself at night, and be ready to sniff out hidden (and possibly otherworldly!) EMF signals with the use of headphones or external speaker.

No previous electronics experience is required to appreciate and use this badge, and it’s a great way to learn more about your world by exploring the different properties of our surroundings.

Please note: The kit does require soldering and runs on two AAA batteries (not included). Ages 11 and up.

Contains:

  • EMF Explorer PCB Board x1
  • 100pF Capacitor (Tan) x2
  • 10uF Capacitor (Blue) x2
  • 4.7uF Capacitor (Sm. Black) x2
  • 100uF Inductors (Lg. Black) x2
  • LED x1
  • IC Chip 2115D x1
  • 100k Resistors (Tan) x2
  • 100ohm Resistors (Blue) x3
  • DPDT Slide Switch x1
  • 1/8" Stereo Jack x1
  • AAA Battery Holders x2
  • Batteries Not Included - Two AAA Required
  • Soldering Iron, Solder and Clippers Required

Instructions Page

What is EMF?

Every conductive material can act as an antenna, receiving small currents from electromagnetic waves, which can be amplified and heard. Conversely, anything that sends out various electronic signals will transmit those signals into the space-time continuum, which can be picked up by a coil of wire, like the inductors on the EMF circuit board. Electromagnetic disturbances from everyday household electronics tend to fall between 20 Hz and 20 KHz, within the range of human hearing. The EMF explorer circuit amplifies those signals up to the human hearing range (by a factor of 1000x).

How Does It Work?

Inductors on the board detect EMF signals. When a changing magnetic field is present near the inductor, it induces a voltage, which can be used to detect the magnetic field.

What Can You Detect?

  • AC Power Supplies: Detect low-frequency hums.
  • Switched-Mode Power Supplies: Detect high-pitched whines or buzzing.
  • Computers and Monitors: Detect internal operational emissions.
  • Dimmer Switches and Motor Speed Controllers: Detect variable-frequency EMF noises.
  • Telecommunication Devices: Detect power circuit emissions.
  • Inductive Loads: Detect humming from transformers and inductors.
  • Microwave Ovens: Detect emissions from transformers and magnetrons.
  • Bluetooth Headphones: Detect internal electronics emissions.
  • Remote Controls: Detect power management and signal modulation emissions.

Explore other devices to see what else you can detect!