Transcript Squishy Circuit Power Point

ITEAMS AUGUST 2016
ENERGY
ELECTRICITY TERMINOLOGY
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One metaphor for electricity is water moving in pipes.
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So VOLTAGE is like electrical pressure. A difference
in pressure causes electricity to flow.
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CURRENT is the electricity’s flow rate.
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This is measured in VOLTS.
This is measured in AMPERES.
(A battery is like a pump, more pressure on one side.)
MULTIMETER
MEASURING VOLTAGE
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Voltage of a battery
pack.
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Which mode?
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Use lowest range
that measures.
Voltage of my
homemade
batteries.
CHALLENGES
SUPER DUPER BATTERIES
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(1) Make a battery with
more voltage than Eric’s.
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(2) Make a battery that
can light an LED.
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Using: nails, copper wire,
two types of dough.
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Set up multimeters.
BONUS TASKS (YOU PICK)
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(3a) Light several
LEDs.
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(3b) Integrate the
battery into an
interesting design
with at least 2
LEDs.
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(4) With 15 nails
make a battery
that delivers:
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(a) maximum
voltage
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(b) maximum
current
WHY DOES IT WORK?
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Probably like a lemon/potato battery. Cream of Tartar
becomes tartaric acid in water (which reacts w baking
soda to make CO 2 to help bread rise!).
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Zinc dissolves in water and releases electrons.
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Zn -> Zn2+ + 2 e-
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The circuit lets electrons flow to the Copper side which
accepts them more than Zinc does.
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Acids by definition can donate H + ions. These combine
with the electrons to make hydrogen gas on the
Copper. Thus more electrons can be accepted, etc.
POWER
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You can make a squishy battery with > 6 V. Why
can’t it make the buzzer or fan work?
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Because Voltage AND Current together are
important.
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Voltage x Current = POWER
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1 volt x 1 ampere = 1 watt
Batteries have different Power Densities (Power per
volume)
POWER
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Voltage x Current =
POWER
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1 volt x 1 amp = 1 watt
My cool battery delivered
2.7 V at 0.4 milliAmp.
Calculate the power.
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2.7 V x 0.0004 A
= .00108 W = 1.08 mW