Elenco Projects 512-692 - Manual (Page 31)

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Project #561
OBJECTIVE: To use the sun to make alarm sounds.
Photo Solar Alarm
Project #562
OBJECTIVE: To use the sun to make space war sounds.
Solar Space War
Set the meter (M2) to the LOW (or 10mA) scale. With the slide switch
(S1) off, make sure you have enough light on the solar cell (B2) for the
meter to read 8 or higher. Now turn on the slide switch and listen to
the space war sounds.
Set the meter (M2) to the LOW (or 10mA) scale. With the slide switch
(S1) off, make sure you have enough light on the solar cell (B2) for the
meter to read 6 or higher. Now turn on the slide switch and listen to
the alarm. Cover the photoresistor (RP) to stop the alarm.
The whistle chip (WC) needs less power to make noise than the
speaker (SP), so this circuit can operate with less light on the solar cell
than projects #559 and #560. But the sound from the circuits with the
speaker is louder and clearer.
You can change the sound from the alarm IC (U2) using the same
variations listed in projects #61-65.
To learn more about how circuits work, visit www.snapcircuits.net or page 85 to find out about our Student Guides.