Motor Generator Project

Push the button on the left side and the light bulb on the right side will light up. It is almost like magic because there are no wires connecting the batteries on the left to the light bulb on the right. In this project you will make two simple electric circuits involving motors and generators. You will then connect the motor's shaft to the generator's shaft using a plastic tube. In one side you will convert electrical energy to mechanical energy. On the other side you will convert mechanical energy to electrical energy. Real cool. Read bellow for details.

Learning Objectives:

  • Learn about Simple Electric Circuits and the basic concepts of electricity and electrical circuits.
  • Using electricity to run mechanical devices such as electric fans, drills, and mixers.
  • Production of electricity using mechanical energy such as water turbines in dams that are connected to electrical generators.
  • Using tools to assemble the circuit and using multimeter to measure the voltage.

Materials used in this project:

  1. One wooden board
  2. One basic lamp holder
  3. One simple switch (push plate)
  4. Two electric motor/generators
  5. One miniature lamp
  6. Motor/Generator connecting tube
  7. Two plastic motor mounts
  8. Six metal screws
  9. Three connection wires
  10. One battery holder
  11. Interlock Tape
  12. Two metal washers

Requires 2 AA batteries

A science fair project:

Electric motor generator kit may be used for a science project, technology project, display project, or an engineering project for your science fair. Your completed project will also be an educational tool for yourself and your classmates who need to understand simple electric circuits, production of electricity and the conversion of energy.


  1. Mount two motor-generators on one side of the wooden block, faced to each other about 8 centimeters (3 1/4 inches) apart.
  2. Cut a length of plastic tube long enough to connect both shafts together while being straight and covering both shafts.
  3. Mount the lamp holder using two screws on the right, near one motor/generator.
  4. Mount the battery holder (using two screws or hook and loop tape) on the left, near the other motor generator.
  5. Use two connector cables to connect the metal contacts of the motor/generator on the right to the two screws of the lamp-holder.
  6. Connect the black wire of the battery holder directly to one of the metal contacts of the motor on the left.
  7. Mount 2 screws near the battery holder about 3 centimeters (1 1/2") apart. These two screws will form a switch, so one of them will hold the switch plate.
  8. Connect the red wire of the battery holder to one of the screws of the switch.
  9. Connect the other screw of the switch to the remaining contact of the motor/generator on the left.

Now your motor/generator system is ready for test. Insert the batteries, screw a lamp in the lampholder and then push the switch to close the circuit in the left. The generator on the right will turn on the light bulb.

What is happening?

The motor/generator on the left will work as a motor. The turning shaft of the motor transfers the mechanical energy to the connecting tube and to the motor/generator on the right that acts as a generator. The generator produces electricity that will light up the light bulb.

Get ready for scientific observations:

Before you continue with the observation and reporting, you must learn how to use your multimeter to measure the electrical voltage between two points. Understand the difference between DC voltage and AC voltage.

Question for your Science Project: How does the voltage change in a motor/generator circuit?

Sample Hypothesis 1: I hypothesize that the voltage does not change in different parts of a motor/ generator circuit.

Sample Hypothesis 2: I hypothesize that the voltage on the motor side is more than the voltage on the generator side.

Experiment: (Observation and Reporting)

  1. Connect the probes of the multimeter to the wires coming out of the battery holder. Read and record the DC voltage while the motor is nor running.
  2. Push the button (close the switch) and repeat your measurement while the motor is running.
  3. Connect the probes of the multimeter to the metal contacts of the generator and measure the AC voltage while the generator is running and the lamp is turned on.
  4. Open the circuit by unscrewing the lamp and then connect the probes of the multimeter to the metal contacts of the generator and measure the AC voltage while the generator is running.

Record your readings in a data table like this:

  DC Voltage on the battery and motor side AC voltage on the generator side
Closed Circuit (Motor running) (With lamp)
Open Circuit (Motor not running) (Without Lamp)

The completed data table may look like this: (Values are not real)

  DC Voltage on the battery and motor side AC voltage on the generator side
Closed Circuit 1.5 2
Open Circuit 2.9 1.3

Analysis and Reporting:

Review the voltage reading you have recorded in the above data table and discuss why the voltage is different in a closed circuit and in open circuit. Also discuss why the electrical voltage produced by generator is different from the voltage produced by the batteries.

Make a graph:

Use your data/results table to draw a graph or create one like this in Excel.

You can order a Kit now

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