CoilCell - Making Magnets Bounce

CoilCell is a compact magnetic actuator that can make magnets move and even jump! In this guide, we will explore how to make a small 5mm diameter ball magnet bounce using the CoilCell, using short pulses to generate motion.

How It Works

CoilCell generates a magnetic field when an electric current passes through its coil. By applying a short pulse, we create a rapid magnetic repulsion that propels the magnet upwards. Depending on the power of the CoilCell module, the effect varies:

• 1W CoilCell: Produces a small bounce of a few millimeters, just enough for the magnet to return to the CoilCell due to attraction
• 2.5W CoilCell: Shoots the magnet much higher (~10cm)

Safety Note

When using the 2.5W 200-Turns CoilCell, always wear eye protection. The repulsion force may cause small magnets to shoot upwards unpredictably.

Generating the Pulse

To generate a pulse, we use the CoilCell library. The following example demonstrates how to make a 5mm ball magnet bounce using an on-time pulse of 20ms, followed by a delay to allow the magnet to be attracted back:

#include <CoilCell.h>

/* Learn more at microbots.io */
/* In this example, we initialize a CoilCell and make a 5mm diameter ball magnet bounce */

#define IN1_pin1 5
#define IN1_pin2 6

CoilCell myCoilCell(IN1_pin1, IN1_pin2);

void setup() {
  myCoilCell.Init(); /* Initialize the CoilCell */
}

void loop() {
  myCoilCell.Bounce(0, 20); /* Bounce the magnet up for 20ms */
  delay(600); /* Attract the magnet back down for 600ms */
}

Understanding the Function:

• Bounce(direction, duration)
  • direction: The pulse direction (0 for normal bounce behavior).
  • duration: Time in milliseconds for the activation pulse.

By tweaking the duration and delay, you can fine-tune the bouncing effect. A longer pulse will push the magnet higher, while a shorter delay may not allow it to return fully before the next bounce.

Conclusion 

This showed us how to make a small ball magnet bounce using CoilCell! Check out the CoilCell GitHub Repository for more code examples and technical documentation!