1. Electricity and Schematics
Our new unit, An Alarming Idea: Designing Alarm Circuits, has the STEMmers learning all about electrical engineering. To introduce this topic I showed the STEMmers the following picture:
We discussed the fact that, indeed, electricity was missing. After discussing what electricity and energy are, we also talked about different types of energy (light, sound, heat, mechanical).
Next, we reviewed how to make a simple circuit, including a battery and a bulb. However, many times the people who create the designs for electrical wiring are not the ones who do the actual wiring. So how are plans made that all people who work with electrical wiring can follow? Schematic diagrams!
To wrap up this lesson, the STEMmers learned some of the basic symbols used for schematic diagramming and created a diagram for the circuit they created earlier.
Next, we reviewed how to make a simple circuit, including a battery and a bulb. However, many times the people who create the designs for electrical wiring are not the ones who do the actual wiring. So how are plans made that all people who work with electrical wiring can follow? Schematic diagrams!
To wrap up this lesson, the STEMmers learned some of the basic symbols used for schematic diagramming and created a diagram for the circuit they created earlier.
2. A Reminder for emily
A part of this story was shared to introduce the STEMmers to the design challenge for this unit. In this story Emily's main chore is to be sure the sheep on her farm always have water in their trough. However, she often forgets. This was definitely a problem! After talking with a neighbor who is an electrical engineer, Emily decides to design and create an alarm circuit that would light a bulb and sound a buzzer whenever the water in the sheep's' trough is too low. The STEMmers will be challenged to do the same thing.
3. Ready for the EDP
The STEMmers now have all of the information they need to successfully complete this challenge. So they will take that information, along with their creativity to begin the steps of the EDP.
With partners, the STEMmers first imagined what their circuits would look like. They are also challenged to create a switch. The trough rests on a beam with a counterweight on the opposite end.
With partners, the STEMmers first imagined what their circuits would look like. They are also challenged to create a switch. The trough rests on a beam with a counterweight on the opposite end.
As long as there is water in the trough, the switch remains open. When the water level drops to almost empty, the counterweight causes the weight to shift, closing the switch. What materials will the teams choose for the switch connection point? How will they get their design to work? I can't wait to see. Below are a few pictures of their work so far. Check under #PHOTOS for more pics.
4. Check Out Their Designs
5. Time to Make Improvements
Each group knew they were successful if closing the switch they designed caused their light bulb to light. If a group's bulb did not light, they needed to improve their design so it would for the next test. If a group's bulb did light, the group was allowed to add a buzzer to their circuit. If this was successful, their alarm would be just like Emily's --- equipped with a light and a buzzer to alert people when more water is needed in the trough. Many of the STEMmers had no problem working their buzzers into their designs successfully!
6. Electric Work in the Real World
On Monday, John and Andy Maddox of Maddox Heating and Air came in with several goodies to share with the 4th graders. The STEMmers got to see some examples of circuitry and the flow of electricity up close. The Maddox brothers also brought in some schematics of a current job they're working on. These schematics were created by a local electrical engineer and will be used to wire a major project in town. Thanks John and Andy for all you shared and for answering all of the questions we had about electricity! If you don't know why birds and squirrels don't usually get electrocuted when they contact power lines, be sure to ask a 4th grader :)