In this lesson we will learn and build some simple circuits using a power source, conductors, resistors, LED lights and switches. We will also learn how to make simple electronics schematic diagrams.
the solderless breadboard is a component used to assemble prototype circuits. The same technology is used by students as well as design engineers. The breadboard has holes called tie points where wires can be inserted. The horizontal rows are connected. Vertical columns are not connected. Some breadboard have a power rail on one or both sides that is connected vertically, it is used for distributing power to your circuit.
Our circuits will require a power source this will usually be a battery but could also be power from a USB or a device. The important thing to know is that all power sources must have plus and minus sides or plus and ground. Many times we will use the power out from a microcontroller. The plus in that case will be labeled 5V or 3.3V or Vin and the minus is GND. On an Arduino UNO the Vin is the same as what ever battery or source that we power the Arduino. the 5V is regulated to be a constant 5V regardless of the power input source, similarly the 3.3V is regulated to 3.3V. GND is zero voltage.
Conductors and Insulators
Also known as wires. We will use them to make connections between our devices using the breadboard. On a schematic diagram they are indicated by solid lines.
LED stands for Light Emitting Diode. What is a diode, you ask? A diode is a device that allows for electricity to flow one way but not the other. We'll get to why that's important a little later. The LED light is a simple, efficient light source that is showing up everywhere. LEDs not only make our world brighter, they are also the way that many electronic devices and robots ?talk? to us. Some example are:
- Your computer's "on" light. That light is an LED!
- Find your favorite toy. If it blinks, the thing blinking is an LED!
- Many cars have headlights that turn on during the day. Many of these are LEDs because of their long lifespans and efficiency.
Experiment with circuits using more LEDs, switches or different values of resistors etc.
Create a Conductor Tester
In our LED circuit the switch was what determined if the light was on or not. The switch completed the circuit when pushed. Suppose we remove the switch and replace it with two jumper wires If we touch the wires together the LED will light. We can use the jumpers to touch a sample material that we want to determine if it is a conductor or insulator. If the LED light up it is a conductor.
Try it yourself.