Lamp, Speaker & Fan in Parallel

Project Number: 80

OBJECTIVE: To show the power drop of components connected in parallel.

Description: Leave the fan off the motor (M1). Turn on the slide switch (S1), the motor spins and the lamp (L1) turns on. Place the fan on the motor and press the press switch. The lamp is not as bright now, because it takes more power from the batteries (B1) to spin the motor with the fan on it, which leaves less battery power available to light the lamp. If you have weak batteries, the difference in lamp brightness will be more obvious because weaker batteries don't have as much power to supply. The speaker (SP) is being used as a low-value resistance here to make the above effects more apparent.