Limericks of Our Lives - Electric
In retirement I have a while, To pen Limericks by the pile, I hope I bring U pleasure, As I write at my leisure, And hope they bring a smile
Electrical Sockets Around the World
Electr-ical-onical Fields are Separate Professions
Electrical and Electronic fields and terms are not the same
The Engineers and Technicians work in a different plane
Electrical deals with Electricity Conversion, Transmission
Electronic circuits do signal, data processing, control, manipulation
Electronics is an extension not a subset of Electrical's reign
Direct (battery) Current is termed DC
The Mains current is Alternating, it’s AC
CCF is Conventional Current Flow
Electron flow is the opposite, you know
These standard terms we currently use, you see
DC, it goes directly on its way
AC travels in alternating play
DC is one-way, that’s direct
AC is two-way, a change-round effect
Neither is better, both methods have their day
DCV is Direct Current Voltage when it’s around
ACV is Alternating Current Voltage, that’s sound
DC has two fixed poles, negative and positive
AC has varying poles, keeping things in perspective
Neither pole is absolute, only relative to the other or ground
A battery’s output is DC of course
Its stored energy is Electromotive Force
In short that’s EMF
But don’t hold your breath
A lonely battery is an open circuit, only a source
An alternator provides Electromotive Force
In motor vehicles, they are the AC source
Pre-1970, they used DC generators
With high maintenance brushes and commutators
The decision to replace them was easy, of course
Electricity Pylons
Closed circuit current will flow out and return
It has a return path, and that’s what we learn
Open circuit current cannot exist
The open air is a very powerful resist
Short circuit current is very high and could burn
Closed circuits are not off, they’re on
In open circuits all current has gone
Closed circuits we use
Short circuits blow a fuse
Two out of three ain’t bad says the song
An EMF is a voltage that’s measured in Volts
High voltage can give a person significant jolts
It’s the current that kills and that’s Amps
If it goes through the heart causing cramps
So respect all your electr-ical-onical faults
A lethal deadly voltage can easily be as low
As 30VAC, 42VDC, so you know. . .
Be on your guard, no foolish acts
With the right conditions these are facts
Don’t be a dead statistic, use a knowledgeable Joe
Electricity can be lethal. Electricity can hurt, harm, burn, maim or even kill. You will hear it quoted often that, “It’s the current that kills and not the voltage”, and that is very true. However, there cannot be sufficient current through a human body without sufficient voltage. It is important to note that the word “sufficient” was used and that “significant” was not used because a “sufficient” deadly voltage can be quite low given the right circumstances or conditions. There are facts and figures published but a general rule of thumb is that 42.4V DC (sometimes quoted as 50V DC) or 30V AC can, but will not always, be lethal to young children, senior citizens and people not in the best of health. And even for healthy people, the surroundings or the environment and also physical conditions can matter significantly due to humidity or open cuts and grazes or fluids or oils on the skin and, of course, the path the current takes through the body organs. Respect all sources of electrical energy.
Electronic Circuit Boards with Components
More Electr-ical-onical Theory
Electricity favors materials called conductors
Items made of these are well dispersed among us
Silver, Copper, Gold and Aluminum/Aluminium
Ranked 1st thru 4th, in their dominion
Even Water, plain H2O, a shock has brung us
What keeps us safe are materials called insulators
They ensure no electric shock will deactivate us
Glass, carbon, rubber, air,
Dry wood, dry paper, and plastic, their
Resistivity properties will not deflate us
Materials of semi-conductors are very useful too
Without them modern life wouldn’t exist and that’s true
Transistors, FPLAs, chips or ICs,
MPUs, CPUs, and components like these
Are part and parcel of everything modern that we do
Resistance to current is called a resistor
A capacity to store energy is called a capacitor
Palin English names components use
From LCD, LED, switch and fuse
An electromagnetic coil is called an inductor
Ohm’s Law is one of the rules
That’s taught in physics in schools
Its V-I-R-tues are such
That we can calculate how much
DC Current flows through resistors, it’s a tool
Handheld Test Multimeters
Kirchoff’s 1st law and how we will work it
Determines how current will flow in a circuit
The sum of the currents entering a junction
Equals the sum of the currents exiting it, the function
Of this law, is current values, we don’t knee-jerk it
Kirchoff’s 2nd law, it deals with volts
It helps technicians determine faults
The sum of all the p.ds around a circuit
Equals the emf, the source, so don’t shirk it
Energy is conserved in circuits like in vaults
WIVes or WAVy navy are formulas we use
To determine the current that will flow in a fuse
The current equals Watts over Volts
Incorrect protection causes fires and faults
The value obtained is the trip level we must choose
Modern buildings, of course, don’t rely on fuses
GFCI or ELCB devices are what we must chooses
But first I’ll say, let me strike a chord
They’re installed already in the mains distribution board
So don’t fret the protection when contemplating your muses
Tesla, Edison, Thevenin and many more
Historically experimented or discovered a rule or law
Watt, Wheatstone, Volta (not Voltaire)
Faraday, Marconi, Ohm and Ampere
Parameters are famous names that we now ignore
Sinewaves and Microwaves oscillate across the nation
From odd-shaped antennas, it’s called propagation
The frequency spectrum is jam-packed, but here’s the thing
Electromagnetic waves are communication’s bling
Without them, no smartphones, no social media, no elation
© 2020 Stive Smyth
