User manual

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If you install the LED as laid out in the set-up plan, the green
LED will also turn on and off. The result is a red and green
flashing light that starts when you push the button switch
and which then gradually fades away. If the LEDs don’t flash,
you have probably installed the normal red LED, which you
can recognize by its somewhat matt colored housing.
The flashing LED
The flashing LED has an electronic switch that consists of a
transistor. Nevertheless, other transistors and components are
still needed. Together they will form a complex circuit and
thus can control the exact timing. Together they are set on a
small piece of silicon, which is then installed next to the LED
crystal. An individual flash circuit will be built later on, so you
can understand how it works.
You can see that the green LED never goes fully dark between
the flashing intervals but continues to glow dimly. The reason
behind this is that despite no current flows through the red
LED crystal, current flows still through the other parts of the
circuit. Thus, we have small current flowing in the off state
causing the green LED to glow dimly.