We take a poetry break.
Poetry in motion.
Electric potential - Optional
An ABAB poem about electricity
Five floors high the structure stands,
As escalators start to rise.
Ten electrons shift like sands,
Trapped beneath the heavy skies.Five volts wait upon the crest,
Frozen tight and forced to stay.
They crave balance, crave a rest,
Longing for the ground away.The switch is open, quiet reigns,
No currents move, no rivers flow.
Like water bound by heavy chains,
Potential waits to strike below.We close the circuit with a click!
A sliding chute is open wide.
The rushing river travels quick,
Down to zero they gladly glide!
Potential: the ability waiting to be used.
Think of potential as “stored ability that has not been used yet.”
Electricity does not literally use a well, a pump, or a syringe.
A waterfall gives us another way to picture it.
The syringe’s push and the pump’s pressure become a difference in height. Water high above the lower basin has energy it can transfer as it falls.
In our poem, 5V becomes a fall from five stories high.
The height difference represents the voltage difference.
Five stories is a poetic picture, not a conversion from volts to height. Electric potential is energy per unit charge; voltage is a difference in that potential.
BUT!!
For a sustained current through our load, we need to close the circuit.
Until then, the voltage can still be there.
The charges have the POTENTIAL to transfer energy, but no complete path through the load.
Close the switch: current flows around the circuit, and energy is transferred to the load.
The water flow represents conventional current. Real electrons drift in the opposite direction; the poem is a metaphor for the energy transfer.
Voltage is electric potential difference.
A potentiometer lets us select a fraction of that difference at its wiper.
Our Arduino analog pin measures the selected potential relative to GND.
Flows UP
The electrons are pushed UP.
The POTENTIAL is the fall.
Electricity actually flows FROM (−) to (+).