Work out pwm duty cycle instantly with clear inputs, formula shown and shareable results.
Duty cycle is on time divided by period. The average voltage of a PWM waveform is supply times duty, but the RMS value is supply times the square root of duty — the distinction matters because heating in a resistive load follows RMS, not average.
PWM
duty = ton / T; Vavg = Vs x duty; Vrms = Vs x sqrt(duty)
Electrical results are planning estimates only. Verify against the applicable wiring rules (IEC 60364, BS 7671, NEC or local code) and have all installation work designed and checked by a qualified electrician.
Because power follows the square of RMS voltage. At 50% duty the RMS voltage is 0.707 Vs, giving exactly half the power, which is correct — but the average voltage of 0.5 Vs would predict only a quarter.
Yes. It must be well above the load's response time: kilohertz for motors, tens of kilohertz to avoid audible noise, and much higher for LED dimming without flicker.