Chapter 13
Basics of Electricity
Learning Objectives
• Identify the nature of electricity and the two
types of electric current.
• List electrical measurements.
• Understand the principles of electrical
equipment safety.
• Examine the main electric modalities used in
cosmetology.
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Learning Objectives (continued)
• Outline other types of electrical equipment that
cosmetologists use and describe how to use
them.
• Explain electromagnetic spectrum, visible
spectrum of light, and invisible light.
• Compare the types of light therapy and their
benefits.
Introduction
• How many of these services could you offer
without using electricity?
• As you study this chapter, you will learn how
important it is for cosmetology professionals to
have a basic working knowledge of electricity
Understand Electricity
Electricity
• The movement of electrons from one atom to
another along a conductor.
• When in motion, exhibits magnetic, chemical, or
thermal effects.
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Understand Electricity (continued)
• Electric current – flow of electricity along a
conductor
• Conductor – material that conducts electricity
– Metal
• Nonconductor – does not conduct electricity
– Rubber, silk, wood, glass, cement
Types of Electric Current
• Direct current (DC) – constant, even-flowing
current going in one direction
– Inverter – apparatus that changes direct current to
alternating current.
• Alternating current (AC) – rapid, interrupted
current changing directions
– Rectifier – apparatus that changes alternating
current into direct current
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Types of Electric Current (continued)
Electrical Measurements
• Volt – measures pressure
• Ampere – measures strength
• Milliampere – 1/1,000th of an ampere
• Ohm – measures resistance
• Watt – measures energy used in 1 second
• Kilowatt – equals 1,000 watts
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Electrical Measurements (continued)
Practice Electrical Equipment Safety
• All electrical equipment should be inspected
regularly to determine whether it is in safe
working order.
• Careless electrical connections and overloaded
circuits can result in an electrical shock, a burn,
or even a serious fire.
Safety Devices
Fuse
Circuit breaker
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Safety Devices (continued)
• Grounding – completes an electric circuit and
carries the current safely away
• Ground fault interrupters – designed to
protect from electrical shock by interrupting a
household circuit when there is a leak in the
circuit
Guidelines for Safe Use of Electrical Equipment
• All the electrical appliances you use should be
UL certified.
• Read all instructions carefully before using any
piece of electrical equipment.
• Disconnect all appliances when not
in use; pull on the plug, not the cord,
to disconnect.
• Inspect all electrical equipment
regularly.
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Guidelines for Safe Use of Electrical Equipment
(continued)
• Keep all wires, plugs, and electrical equipment
in good repair.
• Use only one plug in each outlet.
• Avoid contact with water and metal surfaces
when using electricity.
• Keep electrical cords off the floor and away from
everyone’s feet.
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Guidelines for Safe Use of Electrical Equipment
(continued)
• Do not leave your client unattended while the
client is connected to an electrical device.
• Do not attempt to clean around electric outlets
while equipment is plugged in.
• Do not touch two metal objects at the same time
if either is connected to an electric current.
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Guidelines for Safe Use of Electrical Equipment
(continued)
• Do not step on or place objects on electrical
cords.
• Do not allow electrical cords to become twisted;
this can cause a short circuit.
• Do not attempt to repair electrical appliances on
your own.
One Plug Per Outlet
Understand Electrotherapy
• Electrotherapy – the use of electrical currents to
treat the skin
• Electrode (probe) – an apparatus that conducts
the electric current from the machine to the
client’s skin
• Polarity – positive or negative state of electric
current; electrotherapy devices have a negatively
charged pole and a positively charged pole
Polarity
• Positive pole (anode, red): marked with a P and
a plus (+) sign
• Negative pole (cathode, black): marked with an
N or a minus (–) sign
Modalities
• Galvanic current
• Microcurrent
• Tesla high-frequency current
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Galvanic Current
• Constant, direct current having a positive and
negative pole and producing chemical changes
when it passes through the tissues and fluids of
the body.
• Produces two actions:
– Active electrode – used on area to be treated
– Inactive electrode – opposite from active
electrode
Galvanic Current (continued)
• Iontophoresis – process of introducing watersoluble products in the skin with the use of electric
current
• Cataphoresis – forces acidic substances into
deeper tissues from positive toward negative pole
• Anaphoresis – forces liquids into tissues from
negative toward positive pole
• Desincrustation – used to soften and emulsify
great deposits in hair follicles and pores
Microcurrent
• An extremely low level of electricity that mirrors
the body’s natural electrical impulses
• Can be used for iontophoresis, firming, toning,
and soothing skin
Microcurrent Benefits
• Improves blood and lymph circulation
• Produces acidic and alkaline reactions
• Opens and closes hair follicles and pores
• Increases muscle tone
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Microcurrent Benefits (continued)
• Restores elasticity
• Reduces redness and inflammation
• Minimizes healing time for acne lesions
• Improves the natural protective barrier of the skin
• Increases metabolism
Tesla High-Frequency Current
• Characterized by 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 and scalp
• Primarily heat producing
• Stimulating or soothing, depending on the
method
• Usually made from glass or metal
Tesla Current Benefits
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Stimulates blood circulation
Increases elimination and absorption
Increases skin metabolism
Improves germicidal action
Relieves skin congestion
Identify Other Electrical Equipment
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Hood dryers and heat lamps
Ionic hair dryers and irons
Curling and flat irons
Heating caps
Processing and accelerating machines
Steamers and vaporizers
Light-therapy equipment
Explain Light Energy and Light Therapy
• Electromagnetic spectrum – the name given
to all forms of energy
• Wavelength – the distance between
successive peaks of electromagnetic waves
– Long wavelengths: have a low frequency
– Short wavelengths: have a higher frequency
Waveform
Waveform
• The measurement of the
distance between two
wavelength
Visible Spectrum of Light
• Visible spectrum of light – the part of the
electromagnetic spectrum that can be seen
– Visible light makes up only 35 percent of natural
sunlight.
– Violet has shortest wavelength.
– Red has longest wavelength.
– Infrared is just below red; ultraviolet is just above
violet
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Visible Spectrum of Light (continued)
Invisible Light
• The light at either end of the visible spectrum of
light that is invisible to the naked eye
• Before the visible violet light of the spectrum is
ultraviolet, the shortest and least penetrating light
of the spectrum.
• Beyond visible red light is infrared, which
produces heat.
Ultraviolet (UV) Light
Ultraviolet (UV) Light
• Invisible
• Has short wavelength for higher energy
• Less penetrating than visible light
• Accelerates chemical reactions
• Produces less heat than visible light
• Kills some germs
Types of UV Light
• UVA – has the longest wavelength of the UV
light spectrum and penetrates dermis; damages
collagen and elastin
• UVB – often called the burning light; frequently
associated with sunburns
• UVC – blocked by the ozone layer
Infrared Light
Infrared Light
• Used mainly for hair conditioning treatments and
to process color
• Has longer wavelengths
• Penetrates deeply
• Makes up 60 percent of natural sunlight
• Used to warm muscles
• Can diminish signs of aging
Light Versus Heat and Energy
• Catalysts – used to speed up chemical
reactions; some use heat and absorb energy like
a battery; they pass energy to an initiator and
reaction begins
• Light therapy – also known as phototherapy;
the application of light rays to skin for hair
removal or treatment of wrinkles, capillaries, or
pigmentation
Lasers
• Acronym for Light Amplification by Stimulated
Emission of Radiation
• Photothermolysis – turns light from laser into heat
• Can disable hair follicles
• Can eliminate some wrinkles
© carol.anne/ Shutterstock.com
• Can remove blood vessels and tattoos
How Lasers Work
• By means of a medium (solid, liquid, gas or
semiconductor).
• Medium emits light when stimulated by power.
• Reflective surfaces in chamber create light.
• Light passes back and forth and gains energy.
Laser Hair Removal
• A medical device used
to reduce acne, increase
blood circulation, and
improve collagen content
in the skin
Courtesy of Revitalight.
Light-Emitting Diode (LED)
LED Effects
• Releases light onto skin
• Stimulates specific responses at precise depths
of skin tissues
• Seeks chromophore – color component within
skin such as blood or melanin
• Tissue depth triggers reaction such as
stimulating circulation or reducing bacteria.
Beneficial Effects of LED Therapy
Intense Pulse Light
• Device that uses multiple colors and
wavelengths (broad spectrum) of focused light to
treat spider veins, hyperpigmentation, rosacea
and redness, wrinkles, enlarged hair follicles and
pores, and excessive hair.
• Treatments are provided under the supervision
of a physician.
Summary and Review
• Because many of the devices and pieces of
equipment we use in beauty services are
electrical it is important to have a general
understanding of the basics of electricity.
• We cannot perform various skin care services
safely and effectively without understanding
which form of electrical current will give the best
results for the desired service.
Chapter Review Questions
1. Define electric current.
2. Explain the difference between a conductor
and a nonconductor (insulator).
3. Describe the two types of electric current and
give examples of each.
4. Explain the difference between a volt and an
amp.
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Chapter Review Questions (continued)
5. Define ohm.
6. Define watt and kilowatt.
7. Explain the function of a fuse.
8. What is the purpose of a circuit breaker?
9. What is the purpose of grounding?
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Chapter Review Questions (continued)
10. List at least five steps to take for electrical safety.
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Chapter Review Questions (continued)
11. List and describe the three main electric
modalities (currents) used in cosmetology.
12. What are electromagnetic spectrum of radiation,
visible light, and white light?
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Chapter Review Questions (continued)
13. List and describe the two main types of light
therapy.
14. What are the benefits of LED therapies?
15. Identify the colors of LED lights and their
wavelengths (nm)?
16. Name two important precautions to observe when
using light therapy.