Ηλεκτρικό ρεύμα μονάδα φορτίου στο S.I. προσανατολισμένη κίνηση ηλεκτρικών φορτίων μονάδα φορτίου στο S.I. κουλόμπ (C)

qe=1,6x10-19C Για να μαζέψω 1C πόσα ηλεκτρόνια χρειάζομαι; 6.300.000.000.000.000.000 6,3x1018

Charles Augustine Coulomb 1736-1806 Charles-Augustin de Coulomb (June 14, 1736, Angoulême, France – August 23, 1806, Paris, France) was a French physicist. He is best known for developing Coulomb's law: the definition of the electrostatic force of attraction and repulsion. The SI unit of charge, the coulomb, was named after him.

Συνεχές (DC) Εναλλασσόμενο (AC) Κίνηση φορτίων προς μία κατεύθυνση Αν για κάποιο χρόνο τα φορτία κινούνται προς μια κατεύθυνση και για κάποιο χρόνο στην αντίθετη κατεύθυνση τότε το ρεύμα λέγεται Εναλλασσόμενο (AC) ηλεκτρικό ρεύμα σε αναλογία με το ρεύμα νερού.

Thomas Edison George Westinghouse Πόλεμος των ρευμάτων (DC εναντίον AC) ανάμεσα σε Edison και Nicola Tesla – Westinghouse. Ο Edison προωθούσε το συνεχές ρεύμα σε αντίθεση με τον Westinghouse που ήθελε το AC μια και αυτό μπορουσε να μετασχηματιστεί σε υψηλές τάσεις και να μεταφερθεί με λεπτότερα και άρα φτηνότερα καλώδια σε μεγάλες αποστάσεισ χωρίσ σημαντικές απώλειες. In 1887 there were 121 Edison power stations in the United States delivering DC electricity to customers. When the limitations of Direct Current (DC) were discussed by the public, Edison launched a propaganda campaign to convince people that Alternating Current (AC) was far too dangerous to use. The problem with DC was that the power plants could only economically deliver DC electricity to customers about one and a half miles from the generating station, so it was only suitable for central business districts. When George Westinghouse suggested using high-voltage AC instead, as it could carry electricity hundreds of miles with marginal loss of power, Edison waged a "War of Currents" to prevent AC from being adopted. Despite Edison's contempt for capital punishment, the war against AC led him to become involved in the development and promotion of the electric chair as a demonstration of AC's greater lethal potential versus the "safer" DC. Edison went on to carry out a brief but intense campaign to ban the use of AC or to limit the allowable voltage for safety purposes. As part of this campaign, Edison's employees publicly electrocuted animals to demonstrate the dangers of AC,[29][30] AC electric currents, particularly near 60 Hz frequency, have a markedly greater potential for inducing fatal “Cardiac Fibrillation” than do DC currents. On one of the more notable occasions, in 1903, Edison's workers electrocuted Topsy the elephant at Luna Park, near Coney Island, after she had killed several men and her owners wanted her put to death.[31] His company filmed the electrocution. AC replaced DC in most instances of generation and power distribution, enormously extending the range and improving the efficiency of power distribution. George Westinghouse

πηγή συνεχούς ρεύματος

πηγή εναλλασσόμενου

Ένταση ρεύματος Μονάδα μέτρησης στο S.I. : Amper (Α) Όργανο μέτρησης: Αμπερόμετρο Α dQ

Andre Marie Ampere (1775–1836) Θεμελιωτής της ηλεκτροδυναμικής André-Marie Ampère FRS (20 January 1775 – 10 June 1836), was a French physicist and mathematician who is generally credited as one of the main discoverers of electromagnetism. The SI unit of measurement of electric current, the ampere, is named after him. Ampère demonstrated before the Academy that parallel wires carrying currents attract or repel each other (depending on whether currents are in the same (attraction) or in opposite directions (repulsion)). This laid the foundation of the science of electrodynamics.

~ 0.5 A ~ μερικές Χιλιάδες A

Τάση Μονάδα μέτρησης στο S.I. : Volt (V) Όργανο μέτρησης: Βολτόμετρο V

Alessandro Volta (1745–1827) Εφευρέτης βολταϊκής στήλης Count Alessandro Antonio Anastasio Volta (February 18, 1745 – March 5, 1827) was a Lombard [1][2] physicist known especially for the development of the first electric cell in 1800. In 1776-77 he studied the chemistry of gases, discovered methane, and devised experiments such as the ignition of gases by an electric spark in a closed vessel. Volta also studied what we now call capacitance, developing separate means to study both electrical potential V and charge Q, and discovering that for a given object they are proportional. This may be called Volta's Law of Capacitance, and likely for this work the unit of electrical potential has been named the volt. Around 1791 he began to study the "animal electricity" noted by Galvani when two different metals were connected in series with the frog's leg and to one another. He realized that the frog's leg served as both a conductor of electricity (we would now call it an electrolyte) and as a detector of electricity. He replaced the frog's leg by brine-soaked paper, and detected the flow of electricity by other means familiar to him from his previous studies of electricity. In this way he discovered the electrochemical series, and the law that the electromotive force (emf) of a galvanic cell, consisting of a pair of metal electrodes separated by electrolyte, is the difference of their two electrode potentials. That is, if the electrodes have emfs , then the net emf is . (Thus, two identical electrodes and a common electrolyte give zero net emf.) This may be called Volta's Law of the electrochemical series. In 1800, as the result of a professional disagreement over the galvanic response advocated by Luigi Galvani, he invented the voltaic pile, an early electric battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and silver. Initially he experimented with individual cells in series, each cell being a wine goblet filled with brine into which the two dissimilar electrodes were dipped. The electric pile replaced the goblets with cardboard soaked in brine. (The number of cells, and thus the voltage it could produce, was limited by the pressure, exerted by the upper cells, that would squeeze all of the brine out of the cardboard of the bottom cell.)

+ - ψηφιακό πολύμετρο μπαταρία

Αντιστάτες Μονάδα μέτρησης στο S.I Ωμ (Ω) Όργανο μέτρησης: Ωμόμετρο Ω

Georg Simon Ohm (1789–1854) Georg Simon Ohm (16 March 1789 – 6 July 1854) was a German physicist. As a high school teacher, Ohm began his research with the recently invented electrochemical cell, invented by Italian Count Alessandro Volta. Using equipment of his own creation, Ohm determined that there is a direct proportionality between the potential difference (voltage) applied across a conductor and the resultant electric current – now known as Ohm's law. Using the results of his experiments, Ohm was able to define the fundamental relationship among voltage, current, and resistance, which represents the true beginning of electrical circuit analysis.

Ψηφιακό πολύμετρο αντιστάτης

Πυκνωτές Μονάδα μέτρησης στο S.I Φαράντ (F)

Michael Faraday (1791–1867) Michael Faraday, FRS (22 September 1791 – 25 August 1867) was an English chemist and physicist (or natural philosopher, in the terminology of the time) who contributed to the fields of electromagnetism and electrochemistry. Faraday studied the magnetic field around a conductor carrying a DC electric current, and established the basis for the magnetic field concept in physics. He discovered electromagnetic induction, diamagnetism, and laws of electrolysis. He established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.[2][3] His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts that electricity became viable for use in technology.

Πηνίο

Ονομασία Σύμβολο Πολ/στικός Παράγοντας pico- p = 10-12 nano- n = 10-9 micro- μ = 10-6 milli- m = 10-3 centi- c = 10-2 kilo- k = 103 Mega- M = 106 Giga- G = 109 Tera- T = 1012 Βασική Μονάδα