Manual
-7-
About Your Snap Circuits
®
Parts
TRANSISTORS
The NPN transistor (Q2) is a component that
uses a small electric current to control a large
current, and are used in switching, amplifier, and
buffering applications. Transistors are easy to
miniaturize, and are the main building blocks of
integrated circuits including the microprocessor
and memory circuits in computers.
NPNTransistor (Q2)
LIGHTTUNNEL
The light tunnel (U30) contains 3 red, 3 green,
and 3 blue LEDs, arrayed with mirroring effects.
● When voltage is applied across the (+) and R
(or RED) snaps, the red LEDs light.
● When voltage is applied across the (+) and G
(or GRN) snaps, the green LEDs light.
● When voltage is applied across the (+) and B
(or BLU) snaps, the blue LEDs light.
● When voltage is applied across the (+) and (−)
snaps, circuitry in it lights the LEDs in a
changing pattern.
Light Tunnel (U30)
LEDs
LEDs
(D6 &D8)
The white and color LEDs (D6 & D8) are light
emitting diodes, and may be thought of as a
special one-way light bulbs. In the “forward”
direction, (indicated by the “arrow” in the symbol)
electricity flows if the voltage exceeds a turn-on
threshold brightness then increases. The color
LED contains red, green, and blue LEDs, with a
micro-circuit controlling then. A high current will
burn out an LED, so the current must be limited
by other components in the circuit (Snap
Circuits
®
LEDs have internal resistors added, to
protect them in case you make wiring mistakes).
LEDs block electricity in the “reverse” direction.
The phototransistor (Q4) is a transistor that
uses light to control electric current.
Phototransistor (Q4)
RESISTORS
5.1kW Resistor (R3)
Resistors “resist” the flow of electricity and are
used to control or limit the current in a circuit. This
set includes a 5.1kW resistor (R3) (“k”
symbolizes 1,000, so R3 is really 5,100W).
Materials like metal have very low resistance
(<1W), while materials like paper, plastic, and air
have near-infinite resistance. Increasing circuit
resistance reduces the flow of electricity.