Week 5- Journal

My Assignment Idea

This week, my idea is to design a fire safety mechanism that detects fire, extinguishes it, and gives an alert using a buzzer.

Why I Care

Fires can spread quickly and cause serious harm. A system that alerts and acts immediately can save lives and property.

Inspiration

I was inspired by automatic fire extinguisher balls and Arduino-based fire alarm projects. They showed me how simple sensors and mechanisms can be combined for safety solutions.

Design and Preparation Process

To prepare my assignment, I used TinkerCad to simulate and validate my electrical circuit before physical implementation. TinkerCad allowed me to test the interaction between components, ensure correct voltage values, and visualize the circuit layout.

Modified Instructions (To Meet All Criteria)

1. Place a mini breadboard on the TinkerCad workspace.
   
   

2. Power Supply Setup:
   
   

   • Connect the positive terminal (+) of the 5V DC power supply to the common leg of an ON/OFF switch.
     
     

   • Connect the negative terminal (–) of the DC power supply to the breadboard ground rail (black line).
     
     

3. ON/OFF Switch:
   
   

   • Insert the ON/OFF switch across the central divider of the breadboard.
     
     

   • Connect one output leg of the switch to the positive rail of the breadboard.
     
     

   • This allows the switch to control power distribution to both output components.
     
     

4. Connect the Buzzer (Sound Output):
   
   

   • From the positive rail, use a jumper wire to connect to the positive (+) pin of the buzzer.
     
     

   • Connect the negative (–) pin of the buzzer to the ground rail.
     
     

5. Connect the DC Motor (FAN) (Movement Output):
   
   

   • Place the DC motor (fan) into the breadboard.
     
     

   • Connect the positive terminal of the motor to the positive rail.
     
     

   • Connect the negative terminal of the motor to the ground rail.
     
     

6. Parallel Circuit Justification:
   
   

   • The components (buzzer and DC motor) are connected in parallel, allowing both to receive full voltage and operate independently. This ensures optimal performance of both devices.
     
     

7. Voltage Justification:
   
   

   • A 5V power supply is selected to ensure both the buzzer and motor receive sufficient voltage for effective operation.
     
     

8. Simulation:
   
   

   • The circuit is simulated in TinkerCad to confirm correct connections and functionality before building the physical version.
     
     

I asked my peers for feedback when I noticed the buzzer’s sound was very low while using a 1KΩ resistor.

• They suggested trying a 330Ω resistor to increase the volume.
  
  

• After testing, I found the buzzer’s sound was still worse than expected.
  
  

• Building on their suggestion, I experimented further and removed the resistor completely.
  
  

• This solved the problem because the fan and buzzer were connected in parallel, and the resistor was unnecessarily limiting the current to the buzzer.
  
  

• I helped my peers by sharing my results and explaining why the buzzer worked better without a resistor.
  
  

• My peers helped me by suggesting alternative resistor values and encouraging me to test different options, which led me to the final solution.
  
  

1. 

• Initially, the buzzer did not work, even though it was wired properly according to the basic plan.
  
  

• When the buzzer and LED were swapped, the LED stopped working while the buzzer worked instead.
  
  

• This indicated a problem with how power was being distributed in the circuit, especially with component positioning.
  
  

2.

• I used a voltage supply monitor (Avometer) in TinkerCad to observe current and voltage values.
  
  

• I tested the circuit step by step by visually tracing the connections and checking the power flow through each component.
  
  

• I identified the issue by changing the positions of the LED and buzzer and observing the behavior in TinkerCad.
  
  

• This iterative testing helped narrow down that the issue was related to the position of the resistor in relation to the LDR and output devices.
  
  

 3. 

• The final working solution was achieved by moving the jumper wire connected to Node A of the LDR before the resistor and connecting it to the LED.
  
  

• This small change allowed the circuit to properly divide voltage and current between both outputs (LED and buzzer), making both work as expected.
  
  

• The correction ensured a parallel configuration, maintaining voltage while allowing separate current paths.
  
  

4. 

• The key insight came from trial and error, and carefully observing the multimeter values.
  
  

• This process showed that wire placement order with respect to components (LDR, resistor) directly impacted functionality.
  
  

• No external help was used; instead, I relied on careful testing and logical debugging within TinkerCad.
  
  

 Advice for Others:

• Always check voltage and current readings while testing.
  
  

• Be cautious of component order, placing wires before or after resistors and sensors like LDRs can affect functionality.
  
  

• Test one component at a time to isolate issues.
  
  

• Use simulation tools like TinkerCad to experiment before real-world implementation.

Coolest thing I learned this week:
I learned how to connect a common-anode 7-segment display to show the number 7.

Something I will never forget from this week:
It was the first time during my diploma that I used Tinkercad completely on my own, and I managed to build the circuit so clearly and cleanly that it worked perfectly from the very first try.