Description: A 1N4004 Rectifer Diode (a.k.a flyback diode, snubber diode, kickback diode) is used to prevent back EMF from a fan motor connected to an Arduino Nano.
Notes: The grey band represents the negative side. A forward voltage drop of around .7V can be expected for the 1N4004 diode. A back EMF (reverse voltage spike) gets created when the magnetic field of a coil (like in a motor) collapses. Therefore, in order to avoid damage to electrical components, a rectifier diode which only let’s voltage flow in one direction and not in the other is used to protect from reverse voltage spikes.
Supplies:
1 – Breadboard 400 Points
1 – Arduino Nano
1 – Metal Push-Button 12mm >> Link <<
1 – 1N4004 Rectifier Diode >> Link <<
1 – 10k Resistor
1 – 5V Brushless DC Fan >> Link <<
Arduino Code:
#define fan 6 #define button 16 int fanState = LOW; int lastSwitchVal = LOW; void setup() { pinMode(fan, OUTPUT); pinMode(button, OUTPUT); } void loop() { int switchVal = digitalRead(button); if (switchVal != lastSwitchVal && switchVal == HIGH) { fanState = !fanState; } digitalWrite(fan, fanState); lastSwitchVal = switchVal; }