Elenco Electronics 202 - Manual (Page 6)

Note: If you have Model RS-303, there is additional information in
your other project manual.
The base grid functions like the printed circuit boards found in
most electronic products. It is a platform for mounting parts and
wires (though the wires are usually “printed” on the board).
The blue snap wires are just wires used to connect other
components, they are used to transport electricity and do not affect
circuit performance. They come in different lengths to allow orderly
arrangement of connections on the base grid.
The batteries (B1) produce an electrical voltage using a chemical
reaction. This “voltage” can be thought of as electrical pressure,
pushing electrical “current” through a circuit. This voltage is much
lower and much safer than that used in your house wiring. Using
more batteries increases the “pressure” and so more electricity
flows.
The slide switch (S1) connects (ON) or disconnects (OFF) the
wires in a circuit. When ON, it has no effect on circuit performance.
The press switch (S2) connects (pressed) or disconnects (not
pressed) the wires in a circuit, just like the slide switch does.
Resistors “resist” the flow of electricity and are used to control or
limit the electricity in a circuit. Snap Kits
TM includes 100 Ω (R1), 1KΩ
(R2), 5.1K Ω (R3), 10KΩ (R4), and 100KΩ (R5) resistors (“K”
symbolizes 1,000, so R2 is really 1,000 Ω). Increasing circuit
resistance reduces the flow of electricity.
The adjustable resistor (RV) is a 50K Ω resistor but with a center
tap that can be adjusted between 0 Ω and 50KΩ. At the 0Ω setting,
the current must be limited by the other components in the circuit.
The photoresistor (RP) is a light-sensitive resistor, its value
changes from nearly infinite in total darkness to about 1,000 Ω
when a bright light shines on it.
A light bulb, such as in the 6V lamp (L2) , contains a special wire
that glows bright when a large electric current passes through it.
Voltages above the bulb’s rating can burn out the wire.
The motor (M1) converts elecricity into mechanical motion.
Electricity is closely related to magnetism, and an electric current
flowing in a wire has a magnetic field similar to that of a very, very
tiny magnet. Inside the motor is three coils of wire with many loops.
If a large electric current flows through the loops, the magnetic
effects become concentrated enough to move the coils. The motor
has a magnet inside so, as the electricity moves the coils to align
them with the permanent magnet, the shaft spins.
The speaker (SP) converts electricity into sound. It does this by
using the energy of a changing electrical signal to create
mechanical vibrations (using a coil and magnet similar to that in the
motor), these vibrations create variations in air pressure which
travel across the room. You “hear” sound when your ears feel these
air pressure variations.
The red LED (D1) and green LED (D2) are light emitting diodes,
and may be thought of as 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 (about
1.5V); brightness then increases. A high current will burn out an
LED, so the current must be limited by other components in the
circuit. LED’s block electricity in the “reverse” direction.
Capacitors are components that can store electrical pressure
(voltage) for periods of time, higher values have more storage.
Because of this storage ability they block unchanging voltage
signals and pass fast changing voltages. Capacitors are used for
filtering and oscillation circuits. Snap Kits
TM includes 0.02 μF (C1),
0.1 μF (C2), 10μF (C3), 10μF (C4), 470μF (C5) capacitors, and a
variable capacitor (CV). The variable capacitor can be adjusted
from .00004 to .00022 μF and is used in high frequency radio
circuits for tuning.
-5-
About Your Snap Kits TM Parts
(Part designs are subject to change without notice).