Led array directly on AC mains.

Real-world circuit. Adjust the capacitors on the left to drive different arranges of LEDs and AC input voltages. The normal diodes around the LED array form a rectifier bridge, assuring just direct polarization on the emitting diodes. The stabilizing capacitor on top is optional, and I actually don't use it. This circuit is robust and notablly power-efficient. Almost all energy stored on capacitors is transfered to LEDs without explicit power dissipating components. Circuit works with just one capacitor on the AC input as well, but two provide a partial level of insulation. Note that all nodes are live and may shock you. I've used similar capacitor-coupled power designs for years. Pick capacitors rated double the input AC voltage for building, simulate and try the circuit with smaller capacitor values first.

published 11 years ago