Project 272 oscillator, Oscillator (ii), Oscillator (iii) – Elenco Snap Circuits® Deluxe Sound & Light Combo User Manual

Page 127: Project 273, Project 274

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Project 272

Oscillator

This circuit is an oscillator, because it

produces a repetitive electrical signal on its

own. You hear it as sound waves from the

speaker. The signal is produced by a circuit

inside the keyboard module, but may be

controlled using your Snap Circuits

®

resistors and capacitors, and the keys on

the keyboard. The keys are actually

connecting different resistors inside the

keyboard, similar to the 5.1kW resistor (R3).

Project 273

Oscillator (II)

Project 274

Oscillator (III)

Project 275

Oscillator (IV)

Project 276

Oscillator (V)

Use the preceding circuit, but replace the 1mF

capacitor (C7) with the 0.1mF capacitor (C2). Do

you hear anything? The circuit is producing a

high frequency tone, which may be too high for

your ears to hear, especially if you are older.
Now remove the 0.1mF capacitor from the

circuit. This makes the tone even higher

frequency, and you probably won’t hear

anything now. Dogs have better high frequency

hearing, so maybe your dog can hear it.

Use the preceding circuit, but replace the 100mF

capacitor (C4) with the 470mF capacitor (C5).

The clicks are now farther apart.

Use the preceding circuit, but replace the 5.1kW

resistor (R3) with the 100W resistor (R1). The

frequency of the sound is higher now, and you

hear several clicks a second.

Use the preceding circuit, but replace

the 1mF capacitor (C7) with the 100mF

capacitor (C4). The frequency of the

sound is now so low that you just hear

a clicking sound.

Use the preceding circuit, but replace

the 0.1mF capacitor (C2) with the 1mF

capacitor (C7). The frequency (pitch)

of the sound is lower now.

Build the circuit, and turn the slide switch

(S1). You hear a tone. You can also press

keys on the keyboard (U26) to change the

sound.

Project 279

Oscillator (VIII)

Project 277

Oscillator (VI)

Project 278

Oscillator (VII)

Use the preceding circuit, but replace the 470mF

capacitor (C5) with the 100mF capacitor (C4).

The clicks are faster now.

Use the preceding circuit, but replace the 100mF

capacitor (C4) with the 1mF capacitor (C7). The

frequency of the sound is much higher now, and

you hear a continuous tone.

SCC-350_Manual_Part_C.qxp 7/25/14 2:10 PM Page 15

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