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Pag. 7
Transistors
A transistor is an amplification device. By means of a small
current, a much larger current is controlled. Transistors come in
two flavours, NPN and PNP
-
types, depending on the polarity.
With this kit, you receive a BC557 (PNP) and a BC547 (NPN)
transistor. A transistor has 3 pins: Base, Emitter and Collector.
(Velleman part# BC557B, BC547B)
Phototransistor
E B C
C
B
E
PNP
C B E
C
B
E
NPN
BC547
BC557
A phototransistor is a transistor
that conducts current when the
photocell inside it is sufficiently
exposed to light. You can use it
as a light switch in electrical
circuits.
Velleman part# SGPT5053C )
E
C
