We will use the 555 timer integrated circuit to build an audio oscillator. Using parts from your kit build the following circuit on your protoboard. As you adjust the potentiometer (R3) you should hear the frequency change. The frequency should vary from about 60Hz to 20kHz. We will use an oscilloscope to observe the waveforms at each pin.
Experiements
1) Replace the potentiometer R3 with the light dependent resistor (LDR). The resistance of the LDR device changes with the amount of light hitting it. Observe the frequency change as you allow more or less light to hit the LDR.
2) Replace the 1kΩ resistor R1 with a 470Ω (Yellow, Violet, Brown) resistor. Lowering the resistance will increase the current (Ohm’s law). Observe that the volume level increases when you increase the current.
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