Page 32 - The Basics IA by ETron Circuit Labs

E“Wires A & B create the normally open (NO) Switch”Tron Circuit LabsI t“These wires can i connect to an externalbuzzer or speaker”t“Be sure to twist the ends of wires 21f & 21e together as show in the picture. This is what forms the normally closed (NC) Switch.”t30Lab 16Dual Burglar AlarmObjective:n this Lab you will build a Dual Burglar Alarm circuit hat will sound an alarm when a positive voltage is ntroduced.Step 1 – Take InventoryUsing the Parts Inventory as shown on the right under he “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 beforeyou 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, andhen proceed to Step 3.Step 3 – Do ExperimentTheory:Closing switch S1 will put a positive voltage on the gate of the SCR, causing it to conduct and to sound the alarm. Or, by opening the normally closed switch S2, capacitor C1 will discharge for an instant, and put a positive pulse on the gate of the SCR causing it to conduct. The only way to