Using and Understanding Breadboards

One of the simplest control circuits is the blinking LED.   When testing this circuit, it is often necessary to use a different size resistor.  It is possible to use Ohm's Law to calculate the size of the resistor, but it is faster to just try the circuit before the final construction.  Patented quite recently ( in the 1970s ) the solderless breadboard is used to test a circuit. It was an important technological development as was protected by patents.  The holes in a breadboard are interconnected, and allow each component of the circuit to be connected to the complete circuit.  Please read this week's Tasks and Activities.

  • Arduinos, Raspberry Pis and Micro:bits are all examples of programmable circuits that use very small amounts of electrical current to run the program.  These MCUs will control more powerful circuits.
  • It is always safe practice to test a circuit before the final commitment of the final, soldered circuit is completed.
  • In the example shown here the orange component is a resistor.  The size of the resistor will change the brightness of the LED and protect it from overloading and burning out.

 
  • Click this image to see a larger version of the breadboards we use in class
  • We will construct an LED circuit and see the way in which a resistor can protect an LED
  • Changing the resistor size will change the brightness of the LED
  • Click this image to see a larger view of the breadboard layout
  • Looking carefully at this image you will see how to connect an LED and a resistor to the breadboard
  • An interesting description of breadboards is contained on the ADA-Fruit website.

Tasks and Activities

  1. Put together your breadboard, LED and a resistor and make it glow!
  2. Use a multimeter ( borrowed from the front desk ) to test the size of your resistor.  How does the brightness of the LED change with the size ( Ohms ) of the resistor?
  3. Why are breadboards use to develop prototype circuits?
  4.  What other prototyping tools are used to test a circuit before it is assembled? ( Hint -- Look at this website )

 

  

Don't forget to email your choices/answers to Mr. Widmer by the end of this week.  Keep a copy of that email in your Google Docs folder.