Model 5: Tabletholder

Secured valuables

Grade

5-7

Time required

2 Double lessons

Difficulty level

Model: medium, Programming: medium

Model type

Stationary device as a support for pictures, book or smart devices with optical alarm function when approached, and optical and acoustic alarm function when the placed object is removed.

Download didactic material

MODEL DESCRIPTION / TASK

The students plan and realize a holder for presenting flat objects (pictures, books, smart devices, etc.). The displayed items are secured. A proximity sensor for "pre-alarm" (LED blinking) indicates insufficient distance from the viewer. Removing the presented objects triggers an alarm through both optical and additional acoustic signals. For differentiation, a magnetic switch can be integrated as the main switch.

EVERYDAY RELEVANCE

The protection and securing of objects is familiar to students. Security systems like a Kensington lock, a mobile phone lock in a retail display, a bicycle or ski repair kit near bike paths/slopes, etc., can be shown either in their original form or as pictures. Securing mechanical items presents a particular challenge in this context.

Key questions

How can a flat object be positioned so that its surface is well-visible and presented without obstruction? (Communication)
Where and how are important items showcased, and what are the respective advantages and disadvantages? (Collaboration, critical thinking)
What types of alarm signals are suitable, and how can corresponding physical properties be created if necessary? (Critical thinking)
What aspects of the design need to be considered to ensure the system has a secure base and the items are not at risk of falling or being damaged?

Subject relevance

Informatics

Basics of programming, switches, sensors, time loops

Economics

Sales strategies

Technology

stable building, construction technology

Physics

Capturing physical quantities (shape, movement)

Lesson progression

Information and notes

Methodical and didactic tips

Differentiation options

For differentiation, an additional sensor can be integrated into the system. This allows for "disarming" or "arming" the system by triggering a reed contact. This should be mounted on the side of the system. The reed contact could also be visually enhanced by using a flat magnet attached to an "access card."

Motivational aspects

Securing objects is familiar to students from their everyday lives and brings intrinsic motivation. Independently implementing an actuator can lead to very creative solutions.

Additional material

In the introductory phase, brought-in locks (bike locks, Kensington locks, etc.) can be used. There must be objects to secure (e.g., a tablet, a book, etc.).

Building instructions

Circuit diagram

Functions of the model and their technical solutions

Functions of the Actuators/Sensors	Technical solutions
Capturing a Secured Object	Triggering a Button (Continuous Contact)
Undershooting a Safety Distance	Detection by the Gesture Sensor
Output of the Warning Function "Safety Distance"	Blinking of the red LED
Output of the Alarm Function	Rotational Movement of a Motor with Sound Transmission
Differentiation: Safety Shutdown of the System	Contact via Reedswitch

Material list

Material list for the basic circuit of the Bookstand

Sensors

Functions

1 RGB gesture sensor

Motion sensor on approach

1 Button

Switch contact upon removal of the system

Actuators

Functions

1 LED, red

optical warning function

1 Gear motor

acoustic warning function

Material list for the differentiation task

Sensors

Function

1 Reedswitch

Disarming the system