Controlling Power in LED Lighting

A replacement for LED Lighting Strings

Commonly, many LEDs are connected in-series to form a string. Large lamps will have multiple strings. Each string is current controlled. Over time, the heat dissipated by the LEDs can result in a failure where a whole string of LEDs is disabled. Perhaps you have seen a traffic signal where a portion of the lamp is dark while the reset remains ON.

DIAC Illumination Cells in a Lighting Application.

This figure illustrates how a plurality of DIAC Illumination cells can be arranged in parallel. If a DIAC or LED fails and opens, the remainder of the will be unaffected. If either fails into a short, the capacitance limits the power through the shorted cell while the remainder operate correctly.