User Manual
13
Required parts: 9V battery*, 1K resistor (brown black red gold), 470K resistor (yellow pur-
ple yellow gold), red LED, BC547 transistor, wire jumper.
How it works: In this circuit, the small
current owing through your nger will be
amplied by the transistor.
The base current that runs via your nger
and resistor R1, is amplied by transistor T1.
The amplied current ows through the LED
and R2 making the LED lit.
R3 will prevent the transistor for unwanted
functioning.
HINT: wet you nger to make the LED light up
stronger.