This project replaces a resistor with a capacitor to drop voltage in an AC circuit. This takes advantage of a capacitors reactance in an AC Circuit which can work to limit the current in a much more efficient way than a resistor. the formula for working out the resistance(reactance) the capacitor has is 1/(2pifc) 1 / (2*pi * Frequency * Capacitance).
This circuit uses a 270nF capacitor which gives resistance of 11.8Kohms.