TechyTron Magnetic Alarm STEM Kit

For Classes 3–4, ages 8–10, with adult guidance. No coding or soldering.

Engagement: 35–45 minutes. Explore 5 min · Build 15 min · Measure and discuss 15–25 min.

Included components

• 4 CELL AA BATTERY HOLDER WITH SWITCH / COVER — 1 holder
• AA BATTERY — 4 batteries (1.5 V alkaline AA cells.)
• Regulated 5 V Power Supply with Short-Circuit Protection — 1 power supply (Supplied in a screw-closed enclosure with fitted leads.)
• Small Breadboard / Mini Solderless Board - 400 points — 1 breadboard
• Jumper Wire Combo - Male to Male, Male to Female and Female to Female Breadboard Connecting Wires (10 Qty Each) — 1 set (Colour-coded leads supplied with fitted connectors.)
• Illustrated Activity Guide and Observation Sheet — 1 set
• MC-38 Door Window Sensor Magnetic Switch Home Alarm System — 1 sensor pair (Includes the matching encased magnet. Supplied contact behaviour is configured with the alarm circuit.)
• Magnetic Door Alarm Interface Circuit — 1 piece
• 5 V Active Buzzer — 1 buzzer (Self-oscillating; no external tone generator required.)
• Magnet Position Guide with Ruler — 1 piece

Steps to make it

1. Keep power off. Connect the power unit to the alarm-driver POWER terminals.
2. Connect the magnetic contact to SENSOR and the buzzer to BUZZER, matching the labels.
3. Place the matching magnet beside the contact at the marked closed position.
4. Turn on, then slide the magnet away until the buzzer sounds.
5. Move it back and repeat three times. Record the separation where the alarm changes state.

What children learn

• A magnetic contact can sense a magnet without physical contact between the two housings.
• An interface can turn a sensor state into an alarm response.
• Repeated measurements may differ slightly.

Test challenge

At approximately what magnet separation does the alarm turn on and off? Use the same orientation each time.

Observation task

Write the turn-on and turn-off separations for three trials using the supplied guide.

Expected result

The supplied preset driver keeps the buzzer quiet when the magnet is near and sounds it when the magnet moves away.

Troubleshooting

Use the supplied matching pair and preset driver. Bare reed-switch contact conventions vary; the adult validates the assembled near/far behaviour.

Try next

Rotate the magnet housing and compare whether its orientation changes the switching separation.

Use and supervision

Use only the supplied low-voltage power unit. Switch power off before changing connections. Keep metal objects across the test gap only, never across the battery terminals. Keep liquids away. Adults handle battery access and inspect parts. Kit 8 uses an enclosed motor indicator, not an exposed propeller. Use the buzzer at a comfortable level away from ears.

See how it works

Download the illustrated activity guide

Coming soon. Timing is estimated for guided first use. Illustrations show the learning principle; supplied assemblies are subject to final validation.