Transcript A. Electric Current

Principles of Electricity
Copyright 2014 © SAP
ELECTRICITY
• Electricity is a form
of energy that, when
in motion, exhibits
magnetic, chemical,
or thermal effects.
• Electricity is a flow of
electrons, which are
negatively charged
subatomic particles.
ELECTRICITY
A. Electric Current
– Flow of electricity along a
conductor
B. Conductor
– Any substance, material, or
medium that conducts electricity
C. Insulator (Nonconductor)
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Rubber
Wood
Glass
Cement
ELECTRICITY
D.
Complete Circuit
– The path of an electric current from the generating
source through conductors back to its original source
TYPES OF ELECTRIC CURRENT
A. Direct Current (DC)
– Constant, even-flowing
current, traveling in one
direction
B. Alternating Current
(AC)
– Rapid, interrupted current
flowing in one direction then in
the opposite direction
C. Converters
– Used to change direct current
into alternating current
D. Rectifiers
– Used to change alternating
current into direct current
TYPES OF ELECTRIC CURRENT
Electrical
Measurements
– Volt
– Ampere (AM-peer)
– Milliampere (mil-eeAM-peer)
– Ohm
– Watt
– Kilowatt
Figure 7-16
Figure 7-17
Ohm
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The ohm (symbol: Ω) is the SI derived
unit of electrical resistance, named
after German physicist Georg Simon
Ohm. Although several empirically
derived standard units for expressing
electrical resistance were
developed in connection with early
telegraphy practice, the British
Association for the Advancement of
Science proposed a unit derived from
existing units of mass, length and time
and of a convenient size for practical
work as early as 1861. The definition
of the "ohm" unit was revised several
times. Today the value of the ohm is
expressed in terms of the quantum
Hall effect.
The ohm is defined as a resistance
between two points of a conductor.
AMP
•
The ampere (SI unit symbol: A),
often shortened to amp, is the SI
unit of electric current (dimension
symbol: I) and is one of the seven
SI base units. It is named after
André-Marie Ampère (1775–
1836), French mathematician and
physicist, considered the father of
electrodynamics.
•
An ampere is a unit of measure of the rate
of
electron flow or current in an electrical
conductor. One ampere of current represents one
coulomb of electrical charge (6.24 x 1018 charge
carriers) moving past a specific point in one second.
Physicists consider current to flow from relatively
positive points to relatively negative points; this is
called conventional current or Franklin current.
Watt
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The watt (symbol: W) is a derived
unit of power in the International
System of Units (SI), named after
the Scottish engineer James Watt
(1736–1819). The unit is defined
as joule per second[1] and can be
used to express the rate of
energy conversion or transfer
with respect to time. It has
dimensions of L2MT−3.
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The terms power and energy are frequently confused. Power is the rate at which energy is
generated or consumed and hence is measured in units (e.g. watts) that represent 'energy per unit
time'.
For example, when a light bulb with a power rating of 100W is turned on for one hour, the energy
used is 100 watt hours (W·h), 0.1 kilowatt hour, or 360 kJ. This same amount of energy would light
a 40-watt bulb for 2.5 hours, or a 50-watt bulb for 2 hours. A power station would be rated in
multiples of watts, but its annual energy sales would be in multiples of watt hours. A kilowatt hour
is the amount of energy equivalent to a steady power of 1 kilowatt running for 1 hour, or 3.6 MJ
(1000 watts × 3600 seconds (i.e., 60 seconds per minute × 60 minutes per hour) =
3,600,000 joules = 3.6 MJ).
Terms such as watts per hour are often misused when watts would be correct.[20] Watts per hour
properly refers to the change of power per hour. Watts per hour (W/h) might be useful to
characterize the ramp-up behavior of power plants. For example, a power plant that reaches a
power output of 1 MW from 0 MW in 15 minutes has a ramp-up rate of 4 MW/h. Hydroelectric
power plants have a very high ramp-up rate, which makes them particularly useful in peak load
and emergency situations.
Major energy production or consumption is often expressed as terawatt hours for a given period
that is often a calendar year or financial year. One terawatt hour is equal to a sustained power of
approximately 114 megawatts for a period of one year.
The watt second is a unit of energy, equal to the joule. One kilowatt hour is 3,600,000 watt
seconds. The watt second is used, for example, to rate the energy storage of flash lamps used in
photography, although the term joule is generally employed.
Volt
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The volt (symbol: V) is the derived
unit for electric potential,
electric potential difference
(voltage), and electromotive
force.[1] The volt is named in
honour of the Italian physicist
Alessandro Volta (1745–1827),
who invented the voltaic pile,
possibly the first chemical battery.
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The volt is a measure of electric potential. Electrical
potential is a type of potential energy, and refers to the
energy that could be released if electric current is
allowed to flow. An analogy is that a suspended object is
said to have gravitational potential energy, which is the
amount of energy released if the object is allowed to fall.
In alternating current, the voltages increase, decrease
and change direction at regular intervals. As a result,
voltage for alternating current almost never refers to the
voltage at a particular instant, but instead is the root
mean square (RMS) voltage, which is a way of defining
an effective voltage when calculating power (RMS
voltage × RMS current). In most cases, the fact that a
voltage is an RMS voltage is not specified, but assumed.
TYPES OF ELECTRIC CURRENT
Safety Devices
– Fuse
– Circuit breaker
Electrical Equipment
Safety
– Inspect regularly.
– Never overload circuits.
– Check for UL (Underwriter’s
Laboratory) approval.
– Ensure that appliances are
grounded.
TYPES OF ELECTRIC CURRENT
Hints for the Safe Use of Electricity
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Ensure UL certification.
Study instructions on use of equipment.
Disconnect appliances when not in use.
Inspect all electrical equipment regularly.
Keep wires, plugs, and equipment in good repair.
Use one plug per outlet.
Avoid contact with water or metal when using electricity.
Do not leave the room when client is connected to any
electrical device.
Keep cords off floor to avoid tripping.
Do not attempt to clean around electric outlets while
equipment is plugged in.
TYPES OF ELECTRIC CURRENT
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Hints for the Safe Use of Electricity
Do not touch two metallic objects at the same time if
either is connected to current.
Do not step on or set objects on electrical cords.
Do not allow cords to become twisted or bent.
Disconnect appliances by pulling plug, not cord.
Do not attempt to repair electrical appliances unless
you are qualified.
Never tamper with wiring or plugs to get them to fit into
a receptacle they were not designed for.
ELECTROTHERAPY
Polarity Test #1
– Separate tips and immerse in salt
water.
– Turn the selector switch to galvanic
current.
– As water is decomposed, more active
bubbles will accumulate at negative
pole.
Polarity Test #2
– Place tips of two conducting cords on
two separate pieces of blue
moistened litmus paper.
– Paper under positive pole will turn
red.
– Paper under negative pole will
remain blue.
pH
Conditioners 2.8 - 7
Haircolor 7 - 11
Permanent Waves 4.5 – 9.6
Shampoo 3.5-9.0
Relaxers 10-13
ELECTROTHERAPY
The Galvanic Current is safe and
has been used in medicine for over a
century. The “Galvanic Current," used
today is for cosmetic purposes, which use
to be a very expensive treatment process,
to facilitate the delivery of beneficial
ingredients to the skin. The Galvanic
Current is named after an Italian scientist
Luigi Galvani.
toile
ELECTROTHERAPY
Galvanic Current
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Active electrode
Inactive electrode
Positive pole, anode, red
Negative pole, cathode, black
Positive Pole Results
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Produces acidic reactions
Closes pores
Soothes nerves
Decreases blood supply
Contracts blood vessels
Hardens or firms tissues
ELECTROTHERAPY
Negative Pole Results
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Produces alkaline reactions
Opens pores
Stimulates and irritates nerves
Increases blood supply to skin
Expands blood vessels
Softens tissues
Iontophoresis (eye-ahn-toh-foh-REE-sus)
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Process of introducing water-soluble products into the skin
with the use of electric current
Cataphoresis (kat-uh-fuh-REE-sus)
Anaphoresis (an-uh-for-EES-sus)
Desincrustation (des-in-krus-TAY-shun)
ELECTROTHERAPY
Faradic Current Benefits
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Improves muscle tone
Promotes waste product removal
Increases blood circulation
Relieves congested blood
Increases glandular activity
Stimulates hair growth
Increases metabolism
Sinusoidal Current Benefits
– Supplies greater stimulation; less irritating
than faradic
– Soothes nerves, penetrates muscle tissue
– Best suited for nervous clients
ELECTROTHERAPY
CAUTIONS for Faradic and
Sinusoidal Currents
– Do not use if it causes pain or
discomfort.
– Do not use if face is very florid.
– Do not use if client has gold-filled
teeth, high blood pressure, or
pustular condition of skin.
Tesla High-Frequency
Current
– Has high rate of oscillation or
vibration
– Used for scalp and facial treatments
– Used to treat thinning hair, itchy
scalp, and excessively oily or dry skin
Figure 7-24
ELECTROTHERAPY
Benefits of Tesla Current
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Stimulates circulation of blood
Increases glandular activity
Aids in elimination and absorption
Increases metabolism
Improved germicidal action
Relieves congestion
OTHER ELECTRICAL EQUIPMENT
Conventional Hood Dryer
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For drying hair
Electric Curling Irons
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For curling hair
Heating Caps
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For scalp treatments
Processing or Accelerating Machine
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Accelerates hair services
Steamer or Vaporizer
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For facials
Vibrator
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For massage
Blow Dryer
OTHER ELECTRICAL EQUIPMENT
LIGHT THERAPY
Therapeutic Lamps
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produce same rays as the sun.
produce thermal, mechanical, and chemical effects.
Ultraviolet Rays (UV)
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Short wavelengths
Least penetrating rays
Chemical effects
Benefits of Ultraviolet Rays
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Kill germs
Produce vitamin D on skin
Treat psoriasis
Treat acne
Stimulate production of melanin
LIGHT THERAPY
Disadvantages of Ultraviolet Rays
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May cause sunburn
May cause skin cancer
Application of Ultraviolet Rays
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Lamp should be 30 inches to 36 inches from skin.
Exposure should last only 2 to 3 minutes
Exposure can be increased gradually to 7 to 8 minutes.
Infrared Rays
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60% of natural light
Penetrate the deepest
Produce the most heat
Have long wavelengths
LIGHT THERAPY
SUMMARY
• Electricity plays an important role in the everyday
operations of a cosmetology salon.
• A general understanding of electricity and the various
currents is very important because of the devices and
equipment used in salon services.
• We cannot perform skin care services safely and
effectively without understanding which form of electrical
current gives the best results for the desired service.