The EMF Explorer badge kit lets you tune into the invisible sounds of electromagnetic frequencies that our everyday electronics emit. Each sound tells a story about how these devices operate. It was designed for explorers of all skill levels, and all the components and instructions ensure a successful build. Once assembled, your EMF Explorer board will not only be a tool for discovery but also a wearable piece of tech art, complete with an illuminated design to light your path at night while you explore the electromagnetic frequencies around you.
New to Soldering?
Take a minute to read this soldering guide:
or refer to this infographic:
Soldering Tip!
Keep Your Iron Tip Tinned to prevent oxidation, which reduces solder adherence and heat transfer. Clean the tip with a sponge or brass cleaner, and always leave fresh solder on the tip when not in use.
Safety First!
- Good Ventilation: Avoid inhaling solder smoke. Exhale while soldering to blow fumes away.
- Avoid Eating or Drinking while soldering: Wash your hands after soldering, as solder may contain lead.
- Avoid Burns: Make sure your soldering iron doesn’t touch anything other than the stand while it is hot.
- Careful Cutting: Hold the lead that’s being cut with your fingers or aim it downwards to avoid flying metal. Wear safety glasses to protect your eyes.
Step 1: Gather Your Supplies
Supplies Needed:
- Soldering Iron (40-80w recommended)
- Solder
- Heat-resistant surface
- Fume extractor or well-ventilated work area
- Wire snips for cutting excess leads
- Two AAA batteries
- Headphones with a 3.5mm audio plug
Step 2: Add the Components and Solder parts into place
This photo is your assembly guide. The red text labels on parts indicate that they must be inserted in a specific orientation. Be sure to read the descriptions for each part before inserting it into the board. Solder components in steps so you can check your work as you go. Zoom in as needed so you can read the notes easier!
Step 3: Trim the Excess Leads as you go and Inspect Your Work
Careful Cutting: When cutting excess leads, hold onto the lead with your other hand or aim it down to avoid flying metal. Wear safety glasses.
Inspect Your Work
Ensure that all solder joints connect securely. Reflow solder as needed to ensure a solid bond.
Connect the Batteries and Test
Connect the batteries, plug in your headphones, and hold your EMF board close to an electronic device (e.g., cellphone, power cable, even your soldering iron!). You should hear the device’s EMF sounds in the headphones.
Go Exploring!
Listen to different devices and observe the sounds. Explore the varied sounds from devices like laptops and cell phones. How do Bluetooth headphones sound? Notice changes when connecting to Bluetooth versus transmitting? Get curious about your surroundings and explore everything!
Learn More About the EMF Board and Its Functions
Who’s it for?
This kit allows everyone to explore their surroundings. You can wear the EMF Explorer on a lanyard to help illuminate yourself at night. It’s an excellent tool for those interested in learning more about EMF signals and electronics.
How’s It Made?
The EMF Explorer is created with KiCad. The art was made using vector layers in Affinity Designer, which were then converted to KiCad layers using Gingerbread.
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?
- Power Supplies: Detect low-frequency hums.
- Light switches: hear how the switch is connecting the power circuits that run through walls.
- Computers and Monitors: Detect internal operational emissions.
- Dimmer Switches and Motor Speed Controllers: Detect variable-frequency EMF noises.
- Telecommunication Devices: Detect power circuit emissions.
- Microwave Ovens: Detect emissions from transformers and magnetrons.
- Bluetooth Headphones: Detect internal electronics emissions.
- Remote Controls: Detect IR emitters and other emissions.
Explore other devices to see what else you can detect!
Want to learn more?
If you’re more interested in this, check out this Veritasium video that goes into depth about how electronic signals create a magnetic field around wires to move electrons through them. You can also read NASAs guide to the electromagnetic spectrum.
Links to More Info
Read about the EMF Explorer badge in Make: Volume 90!
Buy a kit from the MakerShed:
Assembled Version
Soldering Kit Version