Data Sheet

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12. Electronic Efciency
Electronic Efciency is dened as the Useful
Power Output divided by the Total Power Input.
Build the circuit to the left and press the switch (62).
The LED (70) will light, but the lamp (76) will not light or
will be very dim. There is resistance built into the LED
(70) to protect it (too much current could damage an
LED), and this resistance is limiting the current in the
circuit, preventing the lamp (76) from lighting. Yet this
circuit shows that the LED (70) is more efcient than the
lamp (76) because it still produces light (useful output
power) even at the lower current.
13. Morse Code Revisited
Build the circuit, press the press switch (61) at a
certain pace and you will hear the Morse code sounds
from the alarm (78). The International Morse Code is
shown below where a dot represents a quick push of
the press switch (61) and a dash represents holding the
press switch (61) for a second. Try sending letters or a
code to a friend and see if they can decode it by listening
to how the sequence of tones you send.
14. Digital Transmission
Replace the alarm (78) with the heart LED (69), then
press the press switch (61) at a certain pace and you
will see the heart LED (69) ashing. This circuit can be
used for sending digital information, such as using a
ber to carry the light sequences from LEDs.
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