Impulzusszélességmodulált

Impulzusszélességmodulált, often abbreviated as PWM, is a technique for digitally controlling analog circuits. It is used to reduce the power delivered to an electrical load by effectively switching the power on and off at a high frequency. The average value of voltage (and thus the average power supplied to the load) is controlled by varying the duration of the 'on' time of the pulse, known as the duty cycle. When the duty cycle is 50%, the output is on for half the time and off for half the time, resulting in half the average voltage.

The key principle of PWM is that the switching is done so rapidly that the load effectively perceives an average voltage. This allows for precise control over parameters like motor speed, light intensity, and the position of actuators. The 'width' of the pulse is modulated to achieve the desired average output. A higher duty cycle means the pulse is wider, resulting in a higher average voltage and more power delivered. Conversely, a narrower pulse (lower duty cycle) leads to a lower average voltage and less power.

PWM is widely employed in power electronics, motor control systems, LED dimming, and audio amplifiers. Its efficiency stems from the fact that the switching elements are either fully on or fully off, minimizing power dissipation during transitions. This makes it a highly effective method for power regulation compared to linear control methods which dissipate excess power as heat.