Data Sheet
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272. Nearby Siren
Build the circuit to the left, then turn on the switch (62) and you will hear
some medium volume sounds of a police siren from the speaker (93).
Also, you will see the lamp (76) is ashing at the same time. The resistance
in the lamp (76) is lower than that in the heart LED (69), allowing more
current to ow through the speaker (93) and thus the volume is higher.
273. Bank Robbery
Connect points C and D with a 4-wire (4) in project #272, turn on the switch
(62) and you will hear gun shots in medium volume and the lamp (76) with
ash at the same time. The lamp (76) simulates ashes from the gun shots.
274. Sound Engineering Tricks
Connect points A and B with the press switch (61) in project #272, turn on the
switch (62) and you will hear a re siren in medium volume and the lamp (76)
will ash. Press and hold the press switch (61) and you will hear a re siren in
medium volume and the lamp (76) will ash at the same time. A change like this
is used by movie set sound engineers to indicate the gun battle may be over.
275. Engineering a Space Battle
Connect points E and F with a 4-wire (4) in project #272. Turn on
the switch (62) and the sounds of space battle will turn on in medium
volume with the lamp (76) ashing with each sound. A sound technician
on a movie set might start a scene with this effect.
276. Music Loudness Reduction
Connect points G and H with a 4-wire (4) in project #272, turn on the
switch (62) and you will hear music in medium volume and the lamp
(76) will ash to the music. The music plays at medium volume because
the resistance in the lamp (76) is in series with the speaker (93) and
reduces the voltage across the speaker.
277. Sound in Water
Replace the switch (62) with the press switch (61) in project #272.
Press and hold the press switch (61) and you will hear some medium
volume sounds of a police siren from the speaker (93). Also, you will
see the lamp (76) is ashing at the same time. Did you know that
sound actually travels more than 4 times faster in water than it does in
air? Water molecules are more densely packed that air molecules so
sounds can be passed more quickly between molecules.
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