Transcript electric circuits 2matchx

There are 2 main circuit types: Series and Parallel.
--A circuit that has only 1 path for
electrons to travel from a
Power Source’s (-) to (+) .
--Any break in the
circuit’s conductors will
stop the electrical current,
since there is only 1
electrical path.
--Ex: old Christmas Lights—
one light burns out, they all
go out.
--A circuit that has
multiple paths for electrons
to travel from the Power
Source’s (-) to the (+) pole.
-A break in a Parallel
Circuit does not stop the
electrical current because
there is more than 1 way
for electrons to reach the
(+) end of the Power
Source.
--Ex: New Christmas Lights continue to work, even if a
light burns out since there are multiple ways for current
to flow.
Moving electricity needs to work against friction in a
wire—the more resistance in the wire, the more Power
is needed to overcome the resistance from friction.
Ohm’s Law states that the speed of an electric
current in a circuit is directly related to the
Resistance and its Power/Voltage.
The Resistance in the Circuit is measured in Ohms
Using Ohm’s Law, you can calculate…
A. How much resistance you need to control the voltage
B. What speed (amps) the current will move
C. How much voltage is needed to power a circuit.
The equation can also
be used to find the
initial Voltage IF the
Resistance and Amps
are known…
A. Needed Resistance (Ohms) = (Voltage / Amps)
B. Needed Amps (A) = Voltage / Resistance
C. Needed Voltage (V) = Amps x Resistance
The current in a hand-held
video game moves at 0.5 A,
with 120 V. What is the
Resistance in this circuit?
Step # 1: list the knowns given
from the problem….
Voltage = 120 V
Amps/current = 0.5 A
Resistance = ?
Step # 2: Use the proper equation
to solve, and do the Math…
Resistance = Voltage / Amps
120 / 0.5 = 24
Step # 3: add the proper unit to your answer….
So a Gameboy that runs on 120 Volts, 0.5 Amps needs
24 Ohms of resistance to work properly.
How much voltage would be needed if the circuits of a
robot need at least 2 Amps of current speed to run
through 100 Ohms of resistance?
Step #1: List the knowns…
Voltage = ?
Amps = 2
Resistance = 100 Ohms
Step #2: Use the proper equation
and do the math…
Voltage = Resistance x Amps
2A x 100 Ohms = 200
Step #3: Finish with the proper Unit
A robot with 100 Ohms of
resistance in the circuits,
requiring 2 A of current
needs 200 Volts of
Electric power.
--Blueprint or technical
drawing of a circuit.
--Uses a standardized symbol
system to show electrical plans
of a circuit.
1. Conductor/Wire
2. Resistor
3. Bulb/lamp
4. Battery/DC source
5. Switch
When too much power enters a household circuit
(Power Surge) the circuit has circuit breakers and
fuses that protect appliances/wires from fires.
Electrical Heat is caused by the Friction of
electricity’s moving electrons.
High Amp electrical current can cause wires to melt
and catch fire from the electrons’ Friction force being
converted into heat energy.
1. Fuses
Circuit conductor
made from a thin
metal strip with a
low melting point.
Too much Electrical current/Friction will melt the fuse
and break the circuit, stopping the electrical current.
2. Circuit Breakers
Circuit conductor made from 2 different metals
pressed together into a strip or use electromagnets.
High Electrical Current
will cause the 2-metal
strip to curl back,
breaking the circuit,
and switching off the
power.
Electromagnetic breakers work when high current
makes the magnet inside stronger and stronger until
the magnet can pull the metal switch open.
Too much electrical energy can be transferred away
from devices and people to protect them.
This is called Grounding
Grounding a circuit gives electric current another path
that carries the electricity to where it wants to be—the
ground.
Lightning rods are placed
on tall buildings to protect
them from lighting strikes.
An attached wire carries
the current safely into the
ground.
Some electrical plugs have a 3rd prong that grounds
them, and will carry electric current away in case of
accidents.
Lastly, metal Faraday Cages can be used to protect
sensitive devices from static electricity, and other
current by absorbing, and sending current to the
ground.