Elenco Electronics 202 - Manual (Page 7)

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Some types of electronic components can be super-miniaturized,
allowing many thousands of parts to fit into an area smaller that
your fingernail. These “integrated circuits” (IC’s) are used in
everything from simple electronic toys to the most advanced
computers. The music, alarm, and space war IC’s (U1, U2, and
U3) in Snap Kits
TM are actually modules containing specialized
sound-generation IC’s and other supporting components (resistors,
capacitors, and transistors) that are always needed with them. This
was done to simplify the connections you need to make to use
them. The descriptions for these modules are given here for those
interested, see the projects for connection examples:
The antenna (A1) contains a coil of wire wrapped around an iron
bar. Although it has magnetic effects similar to those in the motor,
those effects are tiny and may be ignored except at high
frequencies (like in AM radio). Its magnetic properties allow it to
concentrate radio signals for reception. At lower frequencies the
antenna acts like an ordinary wire.
The PNP (Q1) and NPN (Q2) transistors are components that
use a small electric current to control a large current, and are used
in switching, amplifier, and buffering applications. They are easy to
miniaturize, and are the main building blocks of integrated circuits
including the microprocessor and memory circuits in computers.
Projects #124-125 and #128-133 demonstrate their properties. A
high current may damage a transistor, so the current must be
limited by other components in the circuit.
The electromagnet (M3) is a large coil of wire, which acts like a
magnet when a current flows through it. Placing an iron bar inside
increases the magnetic effects. Note that magnets can erase
magnetic media like floppy disks.
The two-spring socket (?1) and 3-spring socket (?Q) are
described on pages 11-12.
The high frequency IC (U5) is a specialized amplifier used only in
high frequency radio circuits. A description of it is given here for
those interested:
High Frequency IC:
INP - input connection (2 points are same)
OUT - output connection
(–) power return to batteries
See project #224 for example of
connections.
INP INP (–)
OUT
(+)
HLD
OUT (–)
TRG
IN1
(–)
IN2
IN3
OUT
IN1
(+) OUT
IN2
(–)
Music IC:
(+) - power from batteries
(–) - power return to batteries
OUT - output connection
HLD - hold control input
TRG - trigger control input
Music for ~20 sec on power-up, then hold
HLD to (+) power or touch TRG to (+)
power to resume music.
Space War IC:
(+) - power from batteries
(–) - power return to batteries
OUT - output connection
IN1, IN2 - control inputs
Connect each control input to (–) power to
sequence through 8 sounds.
Alarm IC:
IN1, IN2, IN3 - control inputs
(–) - power return to batteries
OUT - output connection
Connect control inputs to (+) power to
make five alarm sounds, see project #22
for configurations.
About Your Snap Kits TM Parts (continued)
(Part designs are subject to change without notice).