Elenco Electronics 202 - Manual (Page 18)

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Project #5
OBJECTIVE: To show how a lamp can indicate when a fan is
running.
Build the circuit shown on the left by placing all the parts with a black 1
next to them on the base first. Then, assemble parts marked with a 2.
Finally, place the fan blade on the motor (M1).
When you turn on the slide switch (S1), the fan will spin and the lamp
(L2) should turn on. The fan will take a while to start turning due to
inertia. Inertia is the property that tries to keep a body at rest from
moving and tries to keep a moving object from stopping.
The lamp helps protect the motor from getting the full voltage when the
switch is closed. Part of the voltage goes across the light and the rest
goes across the motor. Remove the fan and notice how the lamp gets
dimmer when the motor does not have to spin the fan blade.
Lamp & Fan in Series
Project #6
OBJECTIVE: To show how an indicator light can be connected
without affecting the current in the motor.
Build the circuit shown on the left.
When you turn on the slide switch (S1), both the fan and the lamp
should turn on. The fan will take a while to start turning due to inertia.
In this connection, the lamp does not change the current to the motor
(M1). The motor should start a little faster than in project #5.
Remove the fan and notice how the lamp does not change in
brightness as the motor picks up speed. It has its own path to the
battery (B1).
Lamp & Fan in Parallel
!
WARNING: Moving parts. Do not touch the fan or
motor during operation.
!
WARNING: Moving parts. Do not touch the fan or
motor during operation.