Elenco Projects 306-511 - Manual (Page 50)

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Project #455
OBJECTIVE: Use the whistle chip and relay to make sound.
Turn on the slide switch (S1) and the relay (S3) opens and closes
continuously. This creates an AC voltage across the whistle chip
(WC), causing it to vibrate and sound.
Relay & Buzzer
Project #456
Project #457
OBJECTIVE: Use the speaker and relay to make sound.
Relay & Speaker
OBJECTIVE: To see how much fun electronics can be.
Electronic Playground
Use the circuit from project #455. Replace the whistle chip (WC) with
the speaker (SP). Turn on the slide switch (S1) and now you generate
a louder sound using the speaker.
Next, replace the whistle chip (WC) with the 6V lamp (L2). Turn on the
slide switch (S1) and the lamp lights.
Uncover the photoresistor (RP) to play a recorded message followed
by music, cover it to stop the music.
Turn on the slide switch (S1), you hear a beep signaling that you may
begin recording. Talk into the microphone (X1) up to 5 seconds, and
then turn off the slide switch (it also beeps after the 5 seconds
expires).
Set the lever on the adjustable resistor (RV) down (towards the
microphone). Push and release the press switch (S2); the green LED
(D2) flashes once while the red LED (D1) stays on longer. The LEDs
will be brighter if your batteries are new.