BUILD CARD · EASY
Magnetic Motor Control
Start a motor by bringing a magnet near the reed switch.
- Time
- 15 min
- Age
- 8+
- Pieces
- 6
- Board
- 10×7
- Build and check a 10×7 snap-grid circuit from a visual diagram.
- A magnet closes the reed contacts and starts the motor without a mechanical button press.
02 / PARTS CHECK
Parts list
- 1×7-snap wireconnector
- 2×3-snap wireconnector
- 1×Motoroutput
- 1×Reed switchswitch
- 1×3V two-cell battery holderpower
03 / ASSEMBLY
How to build the circuit
- 1
Disconnect the battery and clear the base grid before placing any part.
- 2
Match the final diagram one grid position at a time, placing connecting wires and lower layers first.
- 3
Check the direction of every LED, diode, transistor, battery, and other terminal-sensitive part.
- 4
Press every shared snap firmly, check that no wire shorts the battery, then connect power last.
04 / FIELD NOTES
How it works
A magnet closes the sealed reed contacts.
The completed loop powers the motor.
Moving the magnet away stops it.
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05 / TEST
Test and expected result
- What to do
- Approach the reed switch with a magnet while keeping clear of the shaft.
- What to expect
- The motor starts when the magnetic field closes the switch.
06 / SAFETY
Build smart
- Use only the 3V two-cell battery holder.
- Never connect the battery terminals directly together.
- Disconnect the battery before moving any component.
- Keep fingers and loose objects away from the motor shaft.
07 / TROUBLESHOOTING
If it does not work
- Press every overlapping snap down firmly.
- Check the battery direction and replace weak batteries.
- Compare every component position with the final diagram.
08 / FREQUENTLY ASKED QUESTIONS
Questions about this circuit
What is the main idea behind this circuit?
A magnet closes the reed contacts and starts the motor without a mechanical button press.
What should I check first if it does not work?
Press every overlapping snap down firmly.
09 / RELATED BUILDS
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