Science Buddies: "Ask an Expert"

Hy,

I'm a education volunteer in the Netherlands for kids between the 1st and 7th grade. So I did make a project with conductive dough and the most of the part working nice; the LED's, the buzzer, but not the motor. I used a motor of 1.5-4.5V. By 1.5V-240 mA and bu 3V-330mA.
For my circuit I used variously a 9V battery, a 4xAA batterypack and I tryed with a 2AA batterypack, the motor doesn't work. With the LED, the buzzer's no problem. So I wonder what go's wrong? Were do I make something wrong? If there is somebody that give me a hint that would be great.

Thanks for your intention.

Technic - I believe the problem is in the conductivity of the 'dough' and the demands of a higher current for the motor to operate. The LED will only require a voltage of 1.5-3.0V at a mere 10-20 mA to light. The buzzer may not require much more. If you add more salt and be sure there is sufficient water in the dough mix, the motor is more likely to operate. You might also increase your battery voltage to be more like 6 VDC, and use higher capacity batteries like AA or C cells to provide sufficient current. As an alternative, you might use a DC motor that has a lower current requirement to operate.

Rick Marz

Hy, mister Marz

Thanks for thinking with me an your advice. I'm going to try this and let you know if this was the solution.

Kind regards.

Hi Technic - I'd also recommend only using very short lumps of dough to connect the battery pack to the motor. If you use long "tubes" of dough, it will still work for the LEDs but the resistance will be too high for the motor.