Electronics for Kids: Build an Alarm System

In our Electronics for Kids series, we’ve been working with Project EEME to learn about circuits, LEDs, and various electronic components. Today we’re learning how to build an alarm system with Project Tentacle. Check out our past projects: a DIY display and a genius light.

Electronics for Kids: Build an Alarm System

Do you want to set up an alarm for that special drawer in your room? You can store things that you don’t want your little sister (or other person) to get. When she opens the drawer, the alarm will sound and you can stop her. Project Tentacles aims to show you how to build a simple alarm system to accomplish your goal while learning about transistors along the way.

Each of EEME’s project kits comes with online video lessons that teach you how to complete the project and understand how it works. The lessons walk you through everything step by step and ask questions along the way to check for understanding.

The alarm system project is the third project kit. The estimated build time is 1.5 to 2.5 hours. Aiden completed this project in one sitting this time. The wiring was fairly simple compared to the second project and he was getting the hang of following along with the videos. He didn’t even need help from me for this one.

Here are the materials included in the box. You use the breadboard and battery pack from the first project. You’ll find wires, resistors, transistors, and the buzzer.

The lesson begins with a simple buzzer circuit. Turn the battery pack on and the buzzer sounds.

Next, add the tentacles to the project. The two long white wires replace the yellow wire. Turn the battery pack on and nothing happens. Touch the two white wires together and the buzzer sounds. The lesson does a great job of walking you through the ins and outs of circuits and helps you understand what is happening.

Learning about transistors and adding them to the circuit is the next step. The transistor is responsible for making the alarm system function properly.

Your choice of transistor will determine how the buzzer sounds – either when the circuit is closed (with the wires touching) or when the circuit is open (with the wires apart).

Using the correct transistor will allow you to place the alarm system in your drawer. As long as the two white wires are connected, the contents of your special drawer are safe. Opening the drawer will make the white wires come apart and the alarm will sound.

Aiden thought building the alarm system was super cool. What do you think about it?

Head over to EEME’s website and check out their free electronics lessons in addition to their paid project kits and subscriptions.

More Electronics Projects for Kids

• Can You Build a Genius Light? – a fabulous introduction to electronics for kids with the first kit from EEME
• Electronics for Kids: DIY Display – learn how a segmented LED display works and make different sections of the display light up with the second kit from EEME
• Make Your Own LED Robot Toy – use your knowledge of LED circuits to make the eyes light up.
• Create a Push Button Light Up Card – learn how to add an LED light to a greeting card

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