PWMbasert

PWMbasert describes systems and control strategies that use pulse-width modulation (PWM) to regulate power delivered to a load. The term, common in Norwegian technical writing, refers to designs where PWM is the primary mechanism for adjusting voltage, current, or power in electronic circuits and devices.

In a PWM-based design, a switching element such as a MOSFET is driven on and off at a fixed carrier frequency. By changing the duty cycle—the proportion of time the switch is on—the average voltage or current delivered to the load is controlled. This approach can be highly efficient because switching losses are minimized when the device is off, and the load can respond to the averaged value or to a filtered waveform.

Applications are broad. In motor drives, PWM controls speed through duty-cycle variation. In lighting, PWM dims LEDs by reducing average current. In power supplies and chargers, PWM regulates output with high efficiency. Some audio amplifiers (class D) also use PWM to synthesize an analog signal.

Key design considerations include carrier frequency selection, modulation method, and dead-time to protect switches. Where filtering is needed, output filters influence size and cost. EMI and ripple must be managed. Control is implemented with microcontrollers or digital signal processors, and safety features such as overcurrent and overvoltage protection are common.

Variants include fixed- and variable-frequency PWM, unipolar or bipolar outputs, and more advanced techniques such as space-vector modulation used in inverter drives.