home | index | units | counting | geometry | algebra | trigonometry & functions | calculus
analysis | sets & logic | number theory | recreational | misc | nomenclature & history | physics

Final Answers
© 2000-2020 Gérard P. Michon, Ph.D.

Capacitors

Two conductive electrodes
separated by insulating space.

Capacitance is measured in farads (F).
Electroscope. Electric charge is measured in coulombs (C).
Capacity of a sphere. Single-electrode capacitor.
Parallel-plates: Two large planar electrodes separated by a small surface d.
Cylindrical wires or shielding. Many possible configurations.
Leyden jars. Earliests high-voltage capacitors.
Ultracapacitors (supercapacitors). Compact capacitors worth many farads.

Related articles on this site:

Linear filters.
Electronics 101.
Electric capacity.
Fourier Transform.
Hooke's Law and oscillations.
Surface Acoustic Waves (SAW).
Maxwell's equations: Dynamic unification of electricity and magnetism.
Switched capacitor: Faking a resistor with a capacitor and a SPDT switch.

Related Links (Outside this Site)

Homework Question about Capacitor (Yahoo! Answers, 2011-02-15).

Wikipedia : Capacitance | Permittivity

The Mechanical Universe (28:46 each episode) David L. Goodstein (1985-86)
27	Static Electricity (#28) The Electric Field (#29) \| Capacitance and Potential (#30)	31

Capacitors Explained (8:41) The Engineering Mindset (2019-08-25).
High-voltage Breakdown (53:01) by Walter Lewin (MIT 8.02x, #6).
Capacitance, Electric Field Energy (49:23) by Walter Lewin (MIT 8.02x, #7).
Polarization, Dielectrics, Capacitors (50:53) Walter Lewin (MIT 8.02x, #8).

Capacitors

(2019-08-29) The SI unit of capacitance is the farad (F). The unit being named after a person (Faraday) its symbol is capitalized.

Come back later, we're
still working on this one...

Units of measurement

(2019-08-29) Capacity of a sphere. Single-electrode capacitor. Limiting case of a capacitor consisting of two concentric spheres.

Come back later, we're
still working on this one...

Capacitance between Earth and Moon (StackExchange, 2014-05-23).

(2014-05-22) Supercapacitors (SC) = Ultracapacitors Evolution of the electrochemical double-layer capacitor (EDLC).

In 1853, Helmholz first demonstrated the promising idea of an electrochemical double-layer capacitor (EDLC).

In 1913, Gouy and Chapman put forth the "diffuse layer theory".

In 1924, Otto Stern combined both Helmoltz and Gouy-Chapman theory to explain the capacitance:

q_solution = q_Helmoltz + q_Gouy
1/C = 1/C_Helmoltz + 1/C_Gouy

In 1957, at General Electric, Howard I. Becker...

Come back later, we're
still working on this one...

Low voltage electrolytic capacitor, US2800616A (1954/1957) | Howard I. Becker (1918-09-23/1979) GE
Electrical energy storage apparatus, US3288641A (1962/1966) | Robert A. Rightmire (b. 1935-11-17) Sohio

Supercapacitors | Specific surface area | Fractals | Battery University
The silent power of supercapacitors by Patrick Le Fèvre (2018-10-08).
New Method for Balancing Supercapacitors in Series, Using MOSFETs: "Supercapacitor Auto-Balancing" (SAB) by ALD (2013-11-19).

Fun with Ultracapacitors (6:10) by Afroman (Afrotechmods, 2010-12-13).
12 V BoostPack (11:32) by (2012-10-22).
Supercapacitors instead of rechargeable batteries
Ultracapacitor Safety Tips for Car Audio (18:11) by Richard Vedvik (2018-04-08).
Graphene Supercapacitors are about to Change the World (9:17) by Joe Scott (2017-07-03).

visits since August 29, 2019