Array of light emitting diodes

摘要

The invention concerns LED arrays of the type in which one or more "strings" of LEDs such as 6 are series connected across a potential difference as at 8, 10. To compensate for changes in forward voltage of individual LEDs 4, and/or for supply voltage variations, a switching means (which may be formed as a transistor T2, T3) is provided for selectively removing one or more LEDs from the strings. This can for example be done by selectively shorting the chosen LEDs.