Building a Basic Series Circuit

Target Subject: Physical Science

Purpose

To provide a hands-on opportunity to build and examine a basic electrical circuit.

Background information

A series circuit is one in which the electric current follows only one path. An electrical circuit has three main parts, a source such as a battery, wires, and a load such as a radio or a motor. All students do a unit on electricity and circuits at some point in science class. For visually impaired students, many of the same materials and activities can be used. In this activity, the electricity will travel through wires from the battery to the closed switch, through the motor then back to the battery.

Some adaptations and modifications that may assist a student with visual and/or other impairments to build a circuit include using: Velcro to stabilize each component atop a template board with Velcro patches where the components go; traditional single blade switches where the open/close action is more readily observed tactually than other forms of switches; Magna lead wires where the connections at the end of the wires are magnetized and thus easier to connect than standard alligator clips.

Standard electric motors and batteries are generally safe for any student to use.

Preparation

Create a tactile template as described above.

Materials

• Safety goggles
• 11” x 9” white cardboard template
• 4 black Velcro patches (good contrast for low vision)
• Basic circuit components with lead wires attached to each with alligator clips on ends, or Magna leads, and Velcro on underside of each component
• Motor
• 1.5v AA battery
• Battery holder
• Single-knife switch

The motor will need to be fastened to a sturdy base of some sort and then Velcro placed on underside of the base.

Procedure

1. Examine and identify each component.
2. Practice attaching the leads to each other.
3. With the switch in the open (off) position, place components on the template and attach the wires.
4. Observe that the circuit looks like a circle.
5. Close the switch and listen for the sound of the motor.
6. If the motor does not activate, open the switch to stop the electricity flow and check the connections. Retry.

Other Activities using the circuit set-up

One activity our students enjoyed was making fans out of Braille paper and taping them to a wheel which fit on the motor. The air movement created by the fan when the motor was on added another sensory dimension to the activity.

The circuit can be used to examine conductors and insulators. After opening the switch to turn off the flow of electricity, disconnect the circuit at any point. Add an item to the circuit using the alligator clips, close the switch to reestablish the electric city flow, and observe whether the motor runs or not. Insulators will not allow the passage of electricity, conductors will. Try metal objects such as empty soda cans, strips of copper, as well as insulators like wood blocks and plastic and glass containers. When doing this activity keep the circuit closed (on) for only a few seconds as insulators will cause a build up of heat in the power source.

Safety note: Wear goggles at all times when using electricity.