Simple Touch Circuit

This circuit demonstrates the action of transistors.
The current passing through my fingers to my body is amplified by the NPN BC 547 transistor and becomes sufficient to illuminate the red LED.
In the first case, only one transistor is used. While in the second case two transistors of the same type is used. So the amplification in the second case is twice that of the first one, the thing that makes the red LED illuminates brighter and just by a slight touch.

By: Mohammed M. Mahmood