Elenco Upgrade Kit SC500 to SC750 - Manual (Page 38)

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Project #579
OBJECTIVE: To combine U2 with an amplifier.
U2 with Transistor
Amplifier
Project #580
U2 with Transistor
Amplifier (II)
OBJECTIVE: To combine U2 with an amplifier.
Using project #579, remove the diode (D3) to
create a different sound.
OBJECTIVE: To combine U1 with an amplifier.
Project #581
U1 with Transistor
Amplifier (III)
Turn the slide switch (S1) on and the LED’s (D1 & D2) flash as the
speaker (SP) sounds. The output pulses from U2 turns transistor Q2
on and off rapidly. As the transistor turns on, the speaker shorts to
ground and a current flows through it. The current flow through the
speaker causes it to produce a sound. The LED’s show the pulsing
signal from U2 that is turning Q2 on and off.
Using the project #579, replace U2 with U1.
The circuit will now play music.