Does anyone have a way to approximate and RMS voltage from a PWM signal. I want to regulate the RMS voltage sent to a lightbulb, but do not have the room for the inductor and capacitor required to carry 20+ amps of current. I need to feedback a voltage to the PWM controller that is proportional to the RMS voltage of the output. I don't need an EXACT RMS conversion, rather a ratio would be fine since I can adjust the actual voltage fed back to the PWM controller via a resistor divider. For this current design, it will be operating at about 40kHz.
15 years ago