Demonstrating Magnetic Fields with Helmholtz Coils in a Snow Globe -- Episode 525

Helmholtz coils are a common tool for testing with magnetic fields due to their capability to generate an even magnetic field. Comprised of two rings of the same size, wrapped with the same amount of magnetic wire around each, and placed the radius width of the rings apart, Helmholtz coils generate an even sphere of magnetic field between the two coils when the coils are driven with a constant current source. This project attempts to make that magnetic field “visible" by placing a mini set of Helmholtz coils in a snow globe with ferrite shavings.

Supplemental Content:

CAD Files

Bill of Materials

Product Name	Manufacturer	Quantity	Buy Kit
GKX00006 - Development Kit, Arduino MKR1000 IoT Bundle, Components Kit (EXAMPLE)	ARDUINO	1	Buy Now
ST-PH 2-Pin SMT Right Angle Connector[ID:1769]	Adafruit	1	Buy Now
Short Female Header Kit for ItsyBitsy[ID:4174]	Adafruit	1	Buy Now
Short Feather Male Headers - 12-pin and 16-pin Male Header Set[ID:3002]	Adafruit	1	Buy Now
BZX84C2V4LT1G - Zener Single Diode, 2.4 V, 225 mW, SOT-23, 8 %, 3 Pins, 150 °C	onsemi	1	Buy Now
MMBT3904,215 - Bipolar (BJT) Single Transistor, NPN, 40 V, 200 mA, 250 mW, TO-236AB, Surface Mount	NEXPERIA	1	Buy Now
B530C-13-F - Schottky Rectifier, 30 V, 5 A, Single, DO-214AB (SMC), 2 Pins, 550 mV	DIODES INC.	2	Buy Now
RQ73C1J137RBTDF - SMD Chip Resistor, 137 ohm, ± 0.1%, 150 mW, 0603 [1608 Metric], Thin Film	HOLSWORTHY - TE CONNECTIVITY	2	Buy Now
DIY Snow Globe Kit (108mm Diameter) [Adafruit ID:3722]	Adafruit	1	Buy Now
Enameled Copper Magnet Wire – 11 meters / 0.1mm diameter[Adafruit ID:3522]	Adafruit	2	Buy Now
Lithium Ion Polymer Battery - 3.7v 500mAh [Adafruit ID:1578]	Adafruit	1	Buy Now