Amplified light flashes
Because the transistor conducts current in
only one direction, the green LED must
ensure that current can also flow in the
opposite direction. As previous experiments
have shown, the piezo converter supplies an
alternating current. In this case, the green
LED shows the directly generated current,
while the red LED shows the current
amplified by the transistor.
Behind the 12th door you will find a resistor
marked 330 k
Ω
(Orange, Orange, Yellow).
Integrate it into this amplifier circuit using a
transistor. If you now tap softly on the piezo
disc, the red LED will emit a strong flash.
But weak flashes of light also come from the
green LED. Please note that the green LED
is installed in a different way than normal,
namely with the anode (long wire) at the
minus pole of the battery.
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