Flashing LEDs
LED array may include controlling circuits within the same package,
which may range from a simple resistor, blinking or color-changing
control, or an addressable controller for RGB devices.
Higher-powered white-emitting devices will be mounted on heat sinks
and will be used for illumination.
Alphanumeric displays in dot matrix or bar formats are widely
available.
Special packages permit the connection of LEDs to optical fibers
for high-speed data communication links.
Flashing LEDs are used as attention-seeking indicators without
requiring external electronics. Flashing LEDs resemble standard
LEDs but they
contain an integrated voltage regulator and a multivibrator circuit
that causes the LED to flash with a typical period of one second.
In diffused lens LEDs, this circuit is visible as a small black
dot. Most flashing LEDs emit light of one color, but more
sophisticated devices can flash between multiple colors and even
fade through a color sequence using RGB color mixing.