Electric Motors

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• Conversion of energy from one form to another
• Creating useful energy for a certain task
• Can use any type of energy

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• Mechanical to electrical, vise versa
• Actuators, controllers, sensors
• Each can be mechanical or electrical
• Scale can vary greatly

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1. Mechatronics 2. Circuit Drivers 3.
Relays/Transistors 4. Actuators 5. Circuit
Breaker 6. Motors and Generators
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• The portmanteau "Mechatronics" was first coined
  by Mr. Tetsuro Mori, a senior engineer of the
  Japanese company Yaskawa, in 1969.
• Mechatronics may alternatively be referred to as
  "electromechanical systems" or less often as
  "control and automation engineering".

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• The integrated design of products and processes
  that include mechanical and electrical components
  under intelligent control.
• Underlying products are physical in nature
• Sensors and Actuators are used to interface with
  these products.
• There is "intelligence" through imbedded
  computing capability. All these processes are
  highly integrated into sophisticated products and
  processes.

Electromechanical Hydraulic Magnetic, etc
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• Logic-level outputs cant drive a motor directly.
• Solution Relays
• Relays allow one circuit to switch a second
  circuit
• isolates circuit from potentially dangerous
  voltages

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• Main types of relays
• Reed Relay
• General Purpose Relay
• Solid State Relay
• Transistor

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• Advantages
• Little power to energize
• Relatively quiet
• Disadvantages
• Cant control large loads
• Contacts can weld together

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• Advantages
• Can handle very large loads
• Control multiple contacts
• Disadvantages
• Physically large
• Mechanical failure

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• Advantages
• Fast switching
• Silent
• Disadvantages
• Higher cost
• Heat production

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• Advantages
• Fast switching
• Silent
• Disadvantages
• DC only
• Small currents

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Q1 Q2 Q3 Q4 Function ------------------------
------------ 1 0 0 1 Forward 0
1 1 0 Reverse 1 1 0 0
Brake 0 0 1 1 Brake 1 0 1
0 Burn motor 0 1 0 1 Burn
motor
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• Mechanical
• Converts rotary motion of a knob or handle into
  linear displacement via screw or gears
• Rotation of the jack handle is converted
  mechanically into the linear motion of the jack
  head

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• Pneumatic / Hydraulic
• Typically involves a hollow cylinder having a
  piston inserted in it
• The two sides of the piston are alternately
  pressurized/de-pressurized to achieve controlled
  linear displacement of the actuator arm

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• Lead Screw
• Converts rotary motion via motor into linear
  displacement. A lead screw with helical threads
  machined on its circumference rotates, while a
  nut with corresponding helical threads moves the
  actuator linearly

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• Rapidly switching magnetic fields to generate
  motion
• F qv B
• Low acceleration or high acceleration versions
  are used

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• Why?
• Chip Substrate Collapse
• Melting
• Fire
• Why not Fuses?
• Fuses Inexpensive
• Fuses More Reliable
• CBs Can be Reset

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Automatically operated electrical switch designed
to protect an electrical circuit from damaged
caused by overload or a short circuit.
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Features vary based largely on voltage class,
current rating, and the type of circuit
breaker. Common Features 1. Electromagnet or
Bi-metallic strip used to detect and act upon
a fault 2. Control the arc 3. Reclose the
contacts
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• Low current and/or voltage circuit breaker
  Detection occurs within the breaker enclosure
• High current and/or voltage circuit breaker
• Usually utilize a pilot device to sense a fault
  current and to operate the trip opening
  mechanism. Trip solenoid usually operated by a
  separate battery.

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Magnetic Field proportional to current in
coil Tuned mechanical trigger Contacts are
pulled apart in response to Magnetic
force Thermal Material bends or expands with
dissipated heat Contacts pulled apart when
spring-loaded trigger is released http//www.zlan
.com/brk_info.htm Electronically-controlled Co
ntroller reads current value from
sensors Detects when current rises above a
threshold Signals actuators to break contacts
- - In high-power apps, sensors may need to be
separated
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• Arc must be contained, cooled, and extinguished
  in a controlled way
• Vacuum, air, insulating gas, or oil are used as
  the medium in which the arc forms
• Techniques to extinguish the arc

• Lengthening of the arc
• Intensive cooling (in jet chambers)
• Division into partial arcs
• Zero point quenching
• Connecting capacitors in parallel with
• contacts in DC circuits
• Here is why

Even a small spark can ruin some equipment
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• Uses electrical energy to produce mechanical
  work
• Commonly used in refrigerators, washing
  machines, fans, pumps, and computer equipment

• Advantages
• No fossil fuels
• Noise reduction
• Wide range of sizes
• Fewer components
• Disadvantages
• Less powerful
• Battery limitations

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• Types
• AC Induction
• AC Synchronous
• Stepper DC
• Brush DC
• Brushless DC

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• Transforms mechanical energy into electrical
  energy
• Sources of mechanical energy include
• Combustion Engines
• Compressed Gas
• Steam/Gas Turbines
• Solar and Wind

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• DC motors use have a locked ratio. Speed is more
  exact.
• AC motors make more power per weight and dominate
  the market mostly because of power distribution.
• Power distribution is easier for AC because of
  the transformer.

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• Sinusoidal windings and power translation

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