By changing the value of the example in the diagram by a capacitor with a value of 330 nF, a current of approximately 20 mA can be provided, as the
reactance of the 330 nF capacitor at 50 Hz calculates to X_C = \frac{1}{2\pi\;50\,\mathrm{Hz}\;33\cdot 10^{-8}\,\mathrm{F}} \approx 9.646\,\mathrm{k\Omega} and applying
Ohm's law, that limits the current to I \approx \frac{230\,\mathrm{V}}{9.646\,\mathrm{k\Omega}} \approx 24\cdot10^{-3}\,\mathrm{A}. This way up to 48 white LEDs in series can be powered (for example, 3.1 V/20 mA/20000 mcd). Analyzing the circuit of the lamp shown in the image (on the right), at 50 Hz, the 1.2 μF capacitor has a reactance of 2.653 kΩ. By Ohm's law, the current is limited to , assuming that voltage and frequency remain constant. The LEDs are connected in parallel with the 10 μF electrolytic filter capacitor. There are four parallel branches, each having 12 LEDs in series; these branches consume about 20 mA each, or 4 x 20 = 80 mA total. The diodes limit the voltage to about 40 V per branch. Since normally the circuit is connected directly to the mains network without galvanic isolation, a
residual-current circuit breaker is needed in any type of protection circuit used for this kind of
LED light. ==See also ==