Circuit and Schematic Refresher

Part 1: Light an LED on a breadboard

You will be working with your partner on this page. Start by reviewing this presentation

Make sure you have any breadboard

and a power jack with breakout board.
Solder one or find one that's already soldered and ready

and a 12v battery with the Y connector.

You also need an LED, a 1K resistor and some kind of switch.

Do you know or remember how a breadboard works?

Note: breadboards have many configurations!

Using wires, hook the power jack breakout board to the positive (+) and ground (-) bus rails on the breadboard.

Here are the basic building blocks of a circuit.

Here is one possible way to build a basic LED circuit with a switch. This is not the only correct configuration.

Close Up

CHALLENGE: Knowing the following, can you re-arrange the resistor, LED, and the switch on the breadboard and get the LED to light in a different configuration?

A circuit must be complete with a connection to + and - to operate.
We have a 12v battery, which will overload and burn out the LED. A resistor must be used to prevent that over-current situation.
An LED has a long leg (+) and a short leg (-). Wherever the LED is in the circuit, the current must flow into the long leg and out of the short.
If you are including a switch, this circuit should be able to be built in at least four different configurations that would all work.

CHALLENGE:Can you reduce the number of wires in the circuit?

CHALLENGE: How many configurations can you come up with?

Discuss: Frequently used terms

What if your circuit didn't work? Can we collectively name some things that could have gone wrong?

Part 2: Reading Schematics

If you work with circuits for any length of time, or you start designing circuit boards, you'll start to run across a series of symbols designed to simplify circuits into dimensional line images. These images are known as schematics.

In order to move electrons, you need a source of voltage....

A conventional circuit has a positive voltage node and a negative or ground. Here are three examples of each. Label the positive and the negative. Using any resource you want, figure out which is which.

You might see this instead of the symbols above. What is it?

Challenge Drawing Exercises:

Here are some common schematic symbols we'll run across in the next classes.

Redraw each of these on a piece of paper

2. Using any resource you want, add the correct label to each symbol

Polarized Capacitor - Resistor - LED - Integrated circuit - Switch

3. Using any resource you want, figure out what the corresponding component would look like and draw it next to the symbol.

4. Create a one-frame comic where at least one of the components makes a jokey pun to another.

Part 3: Drawing Schematics

Challenge: Now that you know a few symbols. Draw a schematic that uses these five components.

A positive connection
An LED
A 1K resistor
A switch
A negative or ground connection

Here are some pointers:

Start by drawing your components with a small amount of space between them.
Connect the first component to the 2nd with a single line (see image)
Then connect the 2nd component to the third, and so on.
If you want to represent a battery, the final component would connect back to the first; we're not doing that in this case.

Voltage source connected to LED

Part 4: Series and Parallel
this section builds on information from this site

Series: Two components are in series if they share a common node and if the same current flows through them.

Parallel: If components share two or more common nodes, they are in parallel. There are multiple distinct paths that current can take before returning to the source. Where series components all have equal currents running through them, parallel components all have the same voltage drop across them.

Challenge: On paper and on your breadboard.

On paper, draw the series and parallel schematics above modified to have LEDs as specified in the two scenarios below.
Can you figure out how to build the series circuit by replacing two resistors with LEDs? How many LEDs can you run in series before the LEDs don't light?
Can you build the parallel circuit by adding one LED into each of the three paths (you will still need the resistor in each path).

Part 5: Capacitance

Capacitors can collect and store electrical energy. As a direct current flows into a capacitor, it charges with energy and releases an alternating current flow back into the circuit

They are instrumental in circuits where
power fluctuations could be a problem or in audio electronics where frequency filtration is needed.

Can you build this circuit which charges a capacitor then uses the charge to light an LED?

Need to know: How to read an electrolytic capacitor>>

Challenge: On your breadboard.

Build these two circuits, each of which demonstrates the use of capacitors.

What about adding some more capacitors? Are these in series or parallel?

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