Find out
how much power lights, buzzers, bells, and motors require.
Discover
what makes things tick.
What you'll
need
Simple light
bulbs, buzzers, motors, other electronic parts from the B4W
- Deconstruction project and/or store-bought (see Resources)
Batteries (1.5
V and 9V, preferably several of each)
wires with alligator
clips
voltmeter
switches and
light bulb holders or paper clips and brass thumbtacks/fasteners to make your
own
electrical
tape
foam board
various craft
materials to show motor movement.
Getting
started
To make a switch:
Bend a paper clip so that the outer edge sticks up at an angle from about
the middle of the clip.
Tack the flat
end of the clip to the foam board with a brass tack or fastener. Under the
angled end of the clip, put another tack in the foam core, so that if you
fold the clip down, it touches the tack.
Clip an alligator
lead to each tack to use the switch.
For the light
bulb holder, use two paper clips to create leads from the metal end of the
bulb.
You need two
leads - one "in" and one "out" - so think of two different
places to attach clips on the metal.
Attach alligator
leads to the two clips to use the bulb in your circuit.
Predict and
record how many batteries each gadget (light, buzzer, motor, etc.) will need
to work properly.
Test your ideas
by hooking up batteries to the gadgets (securing them to foam board with electrical
tape might help).
To really see
the motors in action, attach something like a pipe cleaner, feather, or construction
paper "spinner" to turn when the motor runs.
Record how much
battery power each needs, and what happens if you use more or fewer batteries
than that.
Try clipping
several wires in a row between the battery and the device - see if this affects
how many batteries a gadget needs.
Use the voltmeter
to test the strength of your batteries. If some of the batteries have different
voltmeter readings, see if it takes fewer, stronger batteries to power your
gadgets.
What happens
if you hook up more than one device to a battery? Can you hook them up in
different arrangements and change the outcome?
What next
Creation
and invention:
Make your devices
artistic as well as functional.
Make a chart
of the amount of battery power that each kind of device needs, and what factors
(size of device, brightness, loudness, etc.) affect that need.
Create a device
that you can use to signal an event, such as ring a bell every time someone
walks by, by adding your circuit to a sensor and programming with LEGO Mindstorms.
Discussion:
Does each device
need the same amount of battery power to run? Which need more? Why?
What happens
if you connect more than one battery to your device?
What everyday
devices in your home use simple circuits like these?
What voltmeter
reading do you get for an old, weak battery? What about a dead battery?
What other sources
of energy are there? What are the differences/similarities between them?
