Circuit Activity Board – A Hands-On Project to Learn Basic Electronics

In this project, we're going to build a Circuit Activity Board, a simple yet interactive way to learn about circuit basics using components like an LDR (Light Dependent Resistor), LED, and Buzzer. This project is ideal for educators, parents, or anyone interested in introducing others to fundamental electronics concepts in a hands-on manner.

Overview

The Circuit Activity Board uses three main electronic components:

• LDR (Light Dependent Resistor)
• LED
• Buzzer

In addition, the board has three custom-made 3D-printed switches that act as bridges to complete different sections of the circuit. Let’s walk through how to build and use the board.

Materials Required

To build the Circuit Activity Board, you’ll need the following materials:

• 1x Light Dependent Resistor (LDR)
• 1x LED
• 1x Buzzer
• 1x CR2032 3V Battery and Battery Holder
• 2N2222 Transistor
• 27k and 220-ohm Resistor
• 10uF Capacitor
• Copper Tape
• 3D-printed switches (or similar lever mechanisms)
• 3mm bolts and nuts
• Soldering iron and wire (for securing components)

3D-Printed Switches

• Begin by printing or sourcing three 3D-printed levers. These will act as switches for your circuit.
• Attach copper tape underneath each switch to ensure electrical conductivity. The copper tape allows the switches to complete the GND line in the circuit.
• Mount each switch onto the board using 3mm bolts and nuts. Each switch should have a 3mm hole for the bolt to pass through.
• These switches will be responsible for completing different sections of the circuit, like a traditional electrical switch.

First Switch – Power Control

• The first switch on the right side acts as the main ON/OFF switch for the board.
• This switch is connected to the GND terminal of the CR2032 battery holder. When turned ON, this switch completes the GND line, allowing power flow to other components on the board.

Second Switch – LDR Activation & GND Bridging

The second switch, positioned in the middle, has two functions:

• It bridges the GND line for the third switch, allowing it to control either the LED or Buzzer.
• It activates the LDR, making it part of the circuit. When this switch is ON, the LDR can now sense light levels and help determine whether the LED or Buzzer will activate.

Third Switch – LED/Buzzer Control

• The third switch, on the left, is used to decide whether the LED or Buzzer will activate.
• If the second switch has activated the LDR, the third switch will control whether the LED or Buzzer turns on based on the LDR’s readings. When the LDR senses darkness, the third switch will either light up the LED or sound the buzzer, depending on its position.

Understanding How It Works

Here’s a quick breakdown of how the circuit functions:

• First Switch (Power ON/OFF): This switch controls the main GND connection for the entire board. When it’s ON, the circuit is powered.
• Second Switch (LDR and GND Bridge): This switch completes the GND line for the third switch and activates the LDR. The LDR will only allow the third switch to work when it senses low light.
• Third Switch (LED or Buzzer Control): This switch is responsible for choosing between the LED or Buzzer. When the LDR detects low light (i.e., darkness), the third switch will either activate the LED or Buzzer based on its position.