## Electrical Engineering

Electrical engineers, abbreviated as EE, design, develop, test, and supervise the manufacturing of electrical equipment.  Electrical & Electronic engineers design things such as power systems, electronics/microelectronics, signal processing, instrumentation & control systems, computers, and computer networks.

### Abbreviations

• ELEC - electric
• ELECDR - electric drive
• EMD - electric motor driven
• EPS - electric power supply
• ELECT - electrical
• ER - electrical resistance
• ELEK - electronic
• ELECTC - electronic control
• EI - electronic interface
• ES - electronic switch
• EVM - electronic voltmeter
• ELMCH - electromechanical
• EE - Electrical Engineer

## Electrical Engineering Subtopics

 Electrical Engineering Cathodic Protection Communications Computer Design Electronics Instrumentation & Controls Power Project

## Electric Wire Materials

• Copper electrical wire - Copper (Cu) is considered the standard in wiring. Most homes and appliances use copper for two reasons. It is easy to mold or bend and it is a good conductor. Copper is rather easy to come by but not as easy as other conductor metals.
• Aluminum electrical wire - Aluminum (Al) is also easy to mold and bend but less of a conductor than copper. If you decide to use aluminum wire that will carry the same amount of electricity as a copper wire, the wire needs to have a larger diameter. Since aluminum is more abundant than copper, it makes it the cheaper of the two.
• Silver electrical wire - Silver (Ag) is the best conductor of electricity for high temperatures. However, it is hard to bend and expensive.
• Alloys in electrical wire - In manufacturing, an alloy may sometimes be used. Aluminum and copper can be used for cost and conductibility.

## electrical Nomenclature & Symbols

• $$S_2$$ = 2-way switch
• $$S_3$$ = 3-way switch
• $$AC$$ = Alternating current
• $$Amp$$ = Ampere
• $$C$$ = Capacitance or capacity
• $$X_c$$ = Capacitive reactance
• $$T_c$$ = Capacitive time constant
• $$Q$$ = Capacitor quality factor
• $$CR$$ = Card reader
• $$CB$$ = Circuit breaker
• $$G$$ = Conductance
• $$DC$$ = Direct current
• $$DB$$ = Distress button
• $$F$$ = Fire alarm pull box
• $$Q$$ = Electric charge
• $$G$$ = Electric conductivity
• $$I$$ = Electric current
• $$J$$ = Electric current density
• $$EL$$ = Electric door latch
• $$ES$$ = Electric door strike
• $$E$$ = Electric field
• $$\phi_e$$  (Greek symbol phi) = Electric flux
• $$Q$$ = Electric load
• $$\eta$$  (Greek symbol eta) = Electric performance
• $$P$$ = Electric power
• $$R$$ = Electric resistance
• $$W$$ = Electric work
• $$f$$ = Frequency
• $$GFCI$$ = Ground fault circuit interrupt outlet
• $$Z$$ = Impedance
• $$L$$ = Inductance
• $$V_l$$ = Inductive load voltage
• $$X_l$$ = Inductive reactance
• $$T_l$$ = Inductive time constant
• $$J$$ = Junction box
• $$KE$$ = Kinetic energy
• $$KB$$ = Knox box - fire department keys
• $$L_x$$ = Light
• $$d$$ = Lost capacitor coefficient
• $$d$$ = Lost coils inductors coefficient
• $$L_m$$ = Luminous flow
• $$c_d$$ = Luminous efficency
• $$c_d$$ = Luminous intensity
• $$NC$$ = Normally closed
• $$NO$$ = Normally open
• $$ML$$ = Magnetic door lock
• $$ME$$ = Mechanical energy
• $$M$$ = Mutual inductance
• $$PB$$ = Panic button
• $$T$$ = Period
• $$\delta$$, $$\; \phi$$  (Greek symbol delta, phi) = Phase constant
• $$PE$$ = Potential energy
• $$P$$ = Power
• $$\omega$$  (Greek symbol omega) = Pulsation
• $$Q$$ = Quality factor of the coils inductors
• $$SD$$ = Smoke detector
• $$S$$ = Switch
• $$S_DIM$$ = Switch with built-in dimmer
• $$TCR$$, $$\; RTC$$ = Temperature coefficient of resistance
• $$\rho$$  (Greek symbol rho) = Resistivity
• $$L$$ = Self inductance
• $$T$$ = Temperature
• $$TX$$ = Transmitter
• $$\epsilon_0$$  (Greek symbol epsilon) = Vacuum permitivity
• $$V$$, $$\; E$$ = Voltage
• $$VCR$$ = Voltage coefficient of resistance
• $$VD$$ = Voltage drop
• $$\lambda$$  (Greek symbol lambda) = Wavelength
• $$WP$$ = Weatherproof outlet

## Electrical Terms

### A

• Actuator  -  A device used to open, close, or control valves.
• Alternating current  -  An electric current that reverses its direction over and over.
• Alternator  -  A device which converts mechanical energy into electrical energy used to maintain a charge in a car battery.
• American Wire Gauge  -  A measure of wire thickness.
• Ammeter  -  An instrument for measuring the flow of electrical current in amperes.
• Amp  -  Amp is a unit of current.
• Amphere  -  A unit of measure for the flow of current in a circuit.
• Amplifier  -  A device that amplifies a relatively small input signal.
• Analog  -  Analog or analogue is a continuous electronic variable signal caring information.
• Analog switch  -  A switching device able to rought analog signals.
• Arcing time of fuse  -  After the breaking of a fuse wire there will be arcing between both melted tips of the wire which will be extinguished at the current zero.

### B

• Battery  -  A storage device for energy and then discharge.  Batteries can be rated by their energy capacity.
• Breaker  -  An automatic switching device that disconnect the power to a circut when the current or heat exceeds a certain level for a certain amount of time.
• Broadband  -  A transmission medium with enough bandwith to cary multiple channels, data, video and voice at the same time.
• Buffer  -  An autio signal device.

### C

• Capacitor  -  Behaves as a charge storage device.  Holds an electric charge when voltage is applied across it and gives up the stored charge when required.
• Capacitance  -  The ability to hold an electric charge.
• Cartridge fuse  -  The fuse wire is enclosed in a transparent glass bulge or tube completely sealed.
• Cell  -  Cells generate energy through a thermal process, chemical or optical.
• Charge  -  Causes objects to feel an attraction or repulsive force toward one another.
• Circuit  -  A closed loop through which electricity can flow.  The flow of current is from positive to negative.
• Conductivity  -  The amount of current that a material can conduct.
• Conductor  -  A material through which heat passes.
• Contacts  -  Components
• Coulomb's law  -  The magnitude of the electrostatic force between two electric charges.
• Current  -  The rate of flow of electricity in a circuit, measured in amperes.
• Current density  -  The amount of electric current flow through a unit value of the area cross-section.
• Current rating of fuse  -  The maximum value of current due to which fuse does not melt.

### D

• Daniell cell  -  A copper vessel containing copper sulfate solution.
• Diode  -  A device allowing the current to flow as a one-way switch only and restricting the current from flowing in the opposite direction.  Diodes allow the current to flow when the anode is positive and the cathode is negative.
• Diode bridge  -  A combination of four diodes that are connected togeather
• Diode types  -  avalanche diode, laser diode, light emitting diode, photodiode, PIN diode, PN junction diode, schottky diode, tunnel diode, varactor diode, and zener diode.
• Direct current (DC)  -  An electric current that flows in only one direction.

### E

• Electrolyte  -  A compound that produces ions when dissolved in water and having either a positive of negative charge.

### F

• Field  -  An invisible space around a charged particle where an electric force is exerted on other charged particles.
• Flux  -  How much of something goes through a given area.
• Forward biased diode  -  The external voltage which is applied across the PN-diode for reducing the potential barrier to constitute the easy flow of current.
• Frequency  -  The number of cycles per sec, measured in Hertz.
• Fuse  -  An safety device that removes electrical current from a circuit when the current is two high.
• Fuse law  -  The current carring capacity of a fuse wire.
• Fuse wire  -  Can carry the normal current without excessive load, but with to much load it rapidly heats up and melts.
• Fuse wire materials  -  Mainly aluminum, antimony, copper, lead, silver, tin, and zinc.
• Fusing factor  -  The ratio of minimum fusing current and current rating of the fuse.

### G

• Generator  -  A mechanical device that produces electrical energy from mechanical energy.

### H

• Hertz  -  A measure of frequency or cps (cycles per second).
• Horsepower  -  A measure of power or the rate of doing work.

### I

• Inductance  -  The measure of an electric conductor or circuit by which an electromotive force is induced in it.

• Inductor  -  An energy storage device which stores energy in the form of a magnetic field.

### K

• Kinetic energy  -  The energy in moving objects or mass.  If it moves, it has kinetic energy.

### L

• Led  -  Emits energy in the form of light instead of energy.

### M

• Magnetic field  -  Magnetic fields never cross, never start or stop, where the field is strongest lines bunch togeather and can be seen clearly seen in the real world.
• Magnetic flux ($$\phi$$ or $$\phi_B$$)  -  The number of magnetic field lines passing through a given closed surface.
• Magnetic switch  -  Depending on the switch configuration for on and off, the switch is activated when the magnetic field is detected.
• Mechanical energy  -  The sum of the change in kinetic energy and potential energy generating from the force of gravity, external forces or the movement released in machine movement.
• Melting time of fuse  -  The time taken by a fuse wire to get broken by melting.
• Minimum fuse current  -  The minimum value of current due to which fuse ments.    Can carry the normal current without excessive load, but with to much load it rapidly heats up and melts.
• Motor  -  Converts the electric energy to mechanical energy.
• Mutual inductance  -  The inductance of a coil due to current in another nearby coil.

### N

• Normally closed  -  The circuit is closed when the switch is not open.
• Normally open  -  The circuit is open when the switch is not operated.

### O

• Ohm  -  A unit of resistance.
• Ohm's law  -  The relationships between power, voltage, current, and resistance.
• Operating time of fuse  -  The time gap between the instant when the overall current starts to flow through the fuse and the instant when the arc in the fuse finally gets extinguished.
• Operational amplifier  -  A voltage amplifier with very high gain.

### P

• Phase constant  -  How much displacement a wave is from an equilibrium or zero position.
• Primary cell  -  A dry cell and not a rechargeable cell.  A chemical reaction between electrodes and electrolites causing a permanent change.
• Parrallel circuit  -  The parts are arranged in branches each going their own way.
• Potential energy  -  The possessed energy by a body due to its relative position in a gravitational field
• Power  -  The rate of doing work and is measured by the amount of foot pounds of work done in a particular unit of time.
• Preset resistor  -  The resistance is adjusted with rotary control pressure on top with a screw driver.
• Prospective current in fuse  -  The value of current which would flow through the fuse immediately after a short circiut occures in the network.

### R

• Rectifier  -  An electrical device that convert alternating current (AC) to direct current (DC).
• Resistance  -  The ability to resist or prevent the flow of current.
• Resistor  -  Resist the flow of electricity.
• Reverse biased diode  -  The external voltage which is applied to the PN junction for strengthening the potential barrier and prevents the flow of current.

### S

• Secondary cell  -  A wet cell and is a rechargable cell.  Generates a current through a secondary cell in the opposite direction of the first cell.
• Self inductance  -  The inductance of a coil or inductor due to its own current.
• Semiconductor  -  A type of material that has an electronic resistance between the metal and the resistance insulator.
• Series circuit  -  The parts are connected end to end.
• Shockley diode  -  Has fast switching operation.
• Shunt  -  Also called a shunt resistor, is a conductor joining two points in a circuit used to limit the speed of the current.
• Solenoid  -  A device made of a coil of wire.  When current is introduced a magnetic field is formed around the coil (electrical energy) and the plunger is pulled in (mechanical work).  When the current is removed the plunger is released.
• Switch  -  A device that opens and closes electrical circuit.

### T

• Thermal insulator  -  Does not conduct heat readily and is used for either heat conservation or personnel protection.
• Transformer  -  A device that uses electromagnetism to convert one current to another current.
• Transducer  -  A voltage output device used for convert energy to another form.
• Transmitter  -  A current output device used for communication electronic signals over a distance.
• Tuner  -  A circuit that can pick signals from a frequency from a group of signals of different frequencies.

### V

• Varactor diode  -  The capacitance varies according to the applied input voltage.
• Variable capacitor  -  Used in tuning the circuit to a required frequency.
• Variable indicator  -  Allows the value of the inductance to be changed.
• Volt  -  A unit of electrical pressure.
• Voltage  -  The amount of pressure that will cause one ampere of current in one ohm of resistance.
• Voltage drop  -  When the voltage at the end of the cable is less than the beginning of the cable.

### Z

Display #
Title
Alternating Current
Alternating Current to Direct Current
API RP 500, Appendix B - Minimum Air Induction Ratio to Achive Adequate Ventilation Using Fugitive Emissions
API RP 500, Section 10
API RP 500, Section 11
API RP 500, Section 12
API RP 500, Section 14
API RP 500, Section 6
API RP 500, Section 8
API RP 500, Section 9
API RP 500, Ventilation
Area Classification Drawing
Control Narrative
Current
Direct Current
Electric Field
Electric Flux
Electric Power
Electric Resistance
Electrical Conductivity
Ohm's Law
Resistor
Resistors in Parallel
Resistors in Series
Solenoid