PWMohjaus

PWMohjaus, or pulse-width modulation control, is a technique used to regulate the average voltage or power delivered to a load by switching a switch on and off at a high frequency while varying the on-time (duty cycle) of each cycle. The average voltage equals the input voltage multiplied by the duty cycle.

PWMohjaus is implemented with power electronics switches such as MOSFETs or IGBTs in configurations including buck, boost, or buck-boost converters, and in motor drive H-bridges. The switching action creates a pulsed waveform whose duty cycle sets the effective output. In many applications a filter is used to smooth the pulses, or the load (such as a motor) may tolerate the pulsed waveform directly.

Common applications include speed control of DC motors, dimming of LEDs, and regulation in switching-mode power supplies. PWMohjausta is also used in audio amplifiers as class D designs, where the duty cycle encodes the audio signal. In DC-DC converters, PWM regulates the output voltage by adjusting duty cycle at a fixed switching frequency.

Advantages of PWMohjaus include high efficiency due to reduced conduction losses in the steady state, and simple integration with microcontroller-based control. Disadvantages include switching losses that increase with frequency, potential electromagnetic interference, and output ripple if filtering is inadequate. Careful selection of switching frequency, topology, and layout is required.

Variants such as fixed-frequency PWM, random or spread-spectrum PWM for EMI reduction, and advanced schemes like space-vector or sinusoidal PWM are used for different motor and power applications. PWMohjaus is a foundational technique in modern power electronics and embedded control systems.