Page 52 - The Basics IA by ETron Circuit Labs

ETron Circuit LabsLab 26 Screaming BoxObjective:In this Lab you will build a Screaming Box circuit that will produce a high pitched squealing sound when the photocell is exposed to light.Step 1 – Take InventoryUsing the Parts Inventory as shown on the right under the “Here’s What You’ll Need” section, place each part needed for this experiment on its corresponding drawing. Observe the schematic symbol for each part. Make sure that you have all the parts ready before you begin Step 2.Step 2 – Build the CircuitUsing the Schematic Diagram and the picture of the completed lab, build the lab experiment with the electronic components. Use the “Check Your Work Here” Box to verify that your wiring is correct, and then proceed to Step 3.Step 3 – Do ExperimentTheory:In this Lab the 555 Timer IC will be used as an astable multivibrator. The resistance of the photocell controls the frequency of the pulses coming from Pin 3 of 555 Timer IC. The more light that hits the photocell, the lower the resistance through it. The lower the resistance, the faster C1 charges and the50