In engineering, electromechanics combines
processes and procedures drawn from electrical
engineering and mechanical engineering.
Electromechanics focuses on the interaction
of electrical and mechanical systems as a
whole and how the two systems interact with
each other.
This process is especially prominent in systems
such as those of DC Machines which can be
designed and operated to generate power from
a mechanical process (generator) or used to
power a mechanical effect (motor).
Electrical engineering in this context also
encompasses electronics engineering.
Electromechanical devices are ones which have
both electrical and mechanical processes.
Strictly speaking, a manually operated switch
is an electromechanical component due to the
mechanical movement causing an electrical
output.
Though this is true, the term is usually understood
to refer to devices which involve an electrical
signal to create mechanical movement, or vice
versa mechanical movement to create an electric
signal.
Often involving electromagnetic principles
such as in relays, which allow a voltage or
current to control another, usually isolated
circuit voltage or current by mechanically
switching sets of contacts, and solenoids,
by which a voltage can actuate a moving linkage
as in solenoid valves.
Before the development of modern electronics,
electromechanical devices were widely used
in complicated subsystems of parts, including
electric typewriters, teleprinters, clocks,
initial television systems, and the very early
electromechanical digital computers.
== History ==
The first electric motor was invented in 1821
by Michael Faraday.
The motor was developed only a year after
Hans Christian Ørsted discovered that the
flow of electric current creates a proportional
magnetic field.
This early motor was simply a wire partially
submerged into a glass of mercury with a magnet
at the bottom.
When the wire was connected to a battery a
magnetic field was created and this interaction
with the magnetic field given off by the magnet
caused the wire to spin.
Ten years later the first electric generator
was invented, again by Michael Faraday.
This generator consisted of a magnet passing
through a coil of wire and inducing current
that was measured by a galvanometer.
Faraday's research and experiments into electricity
are the basis of most of modern electromechanical
principles known today.Interest in electromechanics
surged with the research into long distance
communication.The Industrial Revolution's
rapid increase in production gave rise to
a demand for intracontinental communication,
allowing electromechanics to make its way
into public service.
Relays originated with telegraphy as electromechanical
devices were used to regenerate telegraph
signals.
The Strowger switch, the Panel switch, and
similar devices were widely used in early
automated telephone exchanges.
Crossbar switches were first widely installed
in the middle 20th century in Sweden, the
United States, Canada, and Great Britain,
and these quickly spread to the rest of the
world.
Electromechanical systems saw a massive leap
in progress from 1910-1945 as the world was
put into global war twice.
World War I saw a burst of new electromechanics
as spotlights and radios were used by all
countries.
By World War II, countries had developed and
centralized their military around the versatility
and power of electromechanics.
One example of these still used today is the
alternator, which was created to power military
equipment in the 1950s and later repurposed
for automobiles in the 1960s.
Post-war America greatly benefited from the
military's development of electromechanics
as household work was quickly be replaced
by electromechanical systems such as microwaves,
refrigerators, and washing machines.
The electromechanical television systems of
the late 19th century were less successful.
Electric typewriters developed, up to the
1980s, as "power-assisted typewriters".
They contained a single electrical component,
the motor.
Where the keystroke had previously moved a
typebar directly, now it engaged mechanical
linkages that directed mechanical power from
the motor into the typebar.
This was also true of the later IBM Selectric.
At Bell Labs, in the 1946, the Bell Model
V computer was developed.
It was an electromechanical relay-based device;
cycles took seconds.
In 1968 electromechanical systems were still
under serious consideration for an aircraft
flight control computer, until a device based
on large scale integration electronics was
adopted in the Central Air Data Computer.
== Modern practice ==
Today, electromechanical processes are mainly
used by power companies.
All fuel based generators convert mechanical
movement to electrical power.
Some renewable energies such as wind and hydroelectric
are powered by mechanical systems that also
convert movement to electricity.
In the last thirty years of the 20th century,
equipment which would generally have used
electromechanical devices became less expensive.
This equipment became cheaper because it used
more reliably integrated microcontroller circuits
containing ultimately a few million transistors,
and a program to carry out the same task through
logic.
With electromechanical components there were
only moving parts, such as mechanical electric
actuators.
This more reliable logic has replaced most
electromechanical devices, because any point
in a system which must rely on mechanical
movement for proper operation will inevitably
have mechanical wear and eventually fail.
Properly designed electronic circuits without
moving parts will continue to operate correctly
almost indefinitely and are used in most simple
feedback control systems.
Circuits without moving parts appear in a
large number of items from traffic lights
to washing machines.
Another electromechanical device is Piezoelectric
devices, but they do not use electromagnetic
principles.
Piezoelectric devices can create sound or
vibration from an electrical signal or create
an electrical signal from sound or mechanical
vibration.
To become an electromechanical engineer, typical
college courses involve mathematics, engineering,
computer science, designing of machines, and
other automotive classes that help gain skill
in troubleshooting and analyzing issues with
machines.
To be an electromechanical engineer a bachelor's
degree is required, usually in electrical,
mechanical, or electromechanical engineering.
As of April 2018, only two universities, Michigan
Technological University and Wentworth Institute
of Technology, offer the major of electromechanical
engineering.
To enter the electromechanical field as an
entry level technician, an associative degree
is all that is required.
As of 2016, approximately 13,800 people work
as electro-mechanical technicians in the US.
The job outlook for 2016 to 2026 for technicians
is 4% growth which is about an employment
change of 500 positions.
This outlook is slower than average.
== See also
