Pulse-Width Modulation is the process of rapidly switching a circuit between 0v and battery voltage. Rapidly switching the voltage on and off creates a square wave, which leads to a more stable output voltage. A few examples are: Murata, Raptor, Evolv and YiHi. For a more in-depth explanation of Pulse-Width Modulation click here.
What is the benefit of using PWM?
The benefit of using PWM is the ability to regulate the time that the circuit is on vs off or vice-versa. A good comparison of this is an LED light with adjustable brightness. When fully dimmed, the onboard PWM would be pulsing slowly, but as you turn the brightness up the pulsing gets faster which results in voltage being applied for longer amounts of time. In other words, it’s a way of adjusting “voltage” with a potentiometer instead of a more complicated system like a DNA or SX board. It should be understood that any time the button is pushed, the full voltage of the battery is present across the coils, the switching happens many times per second.
Why does my mod whine or buzz?
Electronic switching is noisy in all applications, especially when unfiltered. The frequency in which most boards run is within the audible range for most humans.
Why won’t my voltmeter read correctly?
Mainly this is due to the oscillation of the voltage; voltmeters generally want a flat input voltage and not one that is oscillating many times per second.