Money Alarm

Click on the arrow in each of the pictures below to see vedios of how kids did the project.

Materials for a Money Alarm


To make  a money alarm, you will need:
  • cardboard
  • paper clips: 2 large, 1 small
  • scissors
  • tape
  • clothes pin (wooden spring-type)
  • coin battery
  • buzzer

How to Make the Alarm



The video to the left shows Luis and Awad as they make a money alarm. This is what they do:

  1. Attach paper clips to clothes pin;
  2. Attach clothes pin to base (this step can come later);
  3. Attach the black wire of buzzer to the first paper clip;
  4. Attach the red wire  of buzzer to the + side of the battery;
  5. Attach wire from the - side of battery to the second paper clip

How a Money Alarm Works


The clothes pin and paper clips are a switch. When the paper clips touch, the circuit is complete. The current runs from the battery

  • through the wire to one of the paper clips,
  • from one paper clip to the second paper clip,
  • from the second paper clip through the wire to the buzzer,
  • from the buzzer through the wire and back to the battery.

Anything that separates the two paper clips opens the circuit. When the circuit is open the buzzer stops. In the money alarm, the paper money separates the two paper clips. 

What do you think would happen if the money was a penny or dime instead of the dollar?