Condensers. General information.
All radio engineering and electronic devices, except for microcircuits and transistors, necessarily have capacitors in their composition. Without capacitors, there is no circuit. Condensers perform a variety of tasks.
From the history of creation
The Leyden jar can be considered as a prototype of the condenser, which was invented by Ewald Jürgen von Kleist from the city of Leiden (Germany) and Peter van Muschenbrook physicist from Holland independently from each other in 1745. But the very first kind of capacitors, which consisted of a pair of conductors separated by a dielectric, is a capacitor or an electric sheet of the Epinus, which was used before the Leyden jar. By the way, the Leyden bank really consisted of an ordinary bank, but glued on the outside and inside with a sheet of tin and covered with a lid of wood. A metal rod was inserted into the lid.
Classification
Condensers are classified by several parameters: dielectric type, resistance, insulation, capacitance, magnitude of losses.
By type of dielectric
- Vacuum (between the plates vacuum).
- Gaseous dielectric.
- Liquid dielectric.
- Solid inorganic dielectric (glass, mica, ceramic, film).
- Solid organic dielectric (paper, metallized-paper).
- Electrolytic, oxide-semiconductor.
- Solid-state capacitor.
By capacity
- Constant.
- Variables.
- Trimmers.
Capacitors also can have cylindrical, spherical, flat form, etc.
Nowadays, tantalum capacitors have been widely used in DC electric circuits; they are used in modern computers, tablet PCs, cell phones, high-speed portable radio transmitters.
Absolutely new kind of capacitors is an ionistor, which is a component for long-term conservation of charge. Such capacitors have a much longer life, an infinite number of charge cycles. It is used for backup power supply of memory circuits of electrical devices.
