Transcript Flowsheets: - Center for STEM Education

Circuits
An electrical circuit is any continuous path for
electrons to flow away from a source of electrical
potential (voltage) and back again.
From the word circle.
Battery
Resistor
For a circuit to work:


Complete circuit (no breaks in the path!).
NO short circuit or NO open circuit.
Given a battery and a light bulb, how would you
connect these two devices together with wire to
turn on the light bulb?
Here’s a simple answer:
Examine this schematic diagram:
Show how to connect the elements with wires to
form the same circuit as in the schematic above.
Examine this schematic diagram:
Show how to connect the elements with wires to
form the same circuit as in the schematic above.
Series vs. Parallel Circuits
Series:

The current goes in one loop only.
Parallel:

The current splits into more than one
direction.
Resistors
“Resist” the flow of electricity.
Resistance depends on the type of material,
its cross-sectional area, & its temperature.
Conductors have low resistance – many free
electrons flow easily
silver, copper, gold,
aluminum, iron
Insulators have very high resistance – few or
no electrons flow
glass, rubber, oil
Electrical Symbols
Here are some electrical symbols
commonly used in representing circuits:
Tips:
We are using the “Snap Circuit, Jr.” kits.
Look over directions in book.
Check where parts are in your kit before
starting. (You will need to put them all back when done.)
The black numbers in the diagram refer to
the order in which the pieces should be
assembled.
Tips:
Before turning on the switch:
1. Check that all circuits match drawing exactly,
including the positive (+) and negative (-)
markings.
2. Check that the connections are securely snapped.
3. Tighten the light bulb, but be very careful not to
break the bulb.
4. Make sure there’s no short circuit.
You must hold the press switch down to turn it on.
When using the fan & many projects with the photo
resistor and the whistle chip, be patient, it takes a
few seconds to start up.
Tips:
Be careful when fan motor is running.
Do not put your face in front of it.
Do not let a whirling part launch into
your eyes!
PROJECTS TO DO:
Project
Project
Project
Project
Project
Project
Project
Project
Project
Project
2 – familiarize yourself with kit & basic circuit
11
If time, try:
12 – series circuits
6 – parallel circuits
#4
13 – adding a switch
#7, #8
15 – adding music
#16
3 – whistle chip
#18
20 – photo resister
#19
22 – Police Siren
#32, 33
27 – Clap Sounds
#34, 35
#38, 39
Last 10 minutes are for clean up!