Information

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1 Basic Principles
1.8 Capacitor
There are various types and constructions of capacitors. Capacitors with fixed
capacitance predominate in modern electronics. The main capacitor types of these are
presented in the following overview:
Fig. 1.8: General overview of today’s most significant capacitor types with fixed
capacitance
Besides the above capacitors with fixed capacitance, there are also capacitors with
variable capacitance. Typical examples are rotary or trim capacitors. They play a rather
subordinate role in modern electronics as compared with the above capacitors.
The critical distinction is between non-polar and polar variants of capacitors with fixed
capacitance. A non-polar capacitor can be operated with DC and AC voltage and it is
irrelevant how it is polarized, as the capacitor’s electrodes are the same type or are
constructed symmetrically.
However, only a DC voltage may be applied to a polar capacitor whose polarity does
not change. The electrodes are distinguished as anode and cathode for these designs.
The anode has to be connected to the positive and the cathode to the negative poten-
tial. The anode and cathode are not the same types for this design. If the polar capaci-
tor is connected incorrectly, damage is caused or there is total failure of the capacitor.
The future development of capacitors includes two essential approaches. On the
one hand, the aim is to advance miniaturization in order to keep up with increasing
integration density in the electronics industry. On the other hand, the clear focus lies
in increasing capacitance, as the capacitor, like the classical rechargeable battery, is a
potential energy storage device and with increasing capacitance and advancement it is
becoming increasingly attractive.
The important characteristics and parameters of a capacitor are presented and
explained in Chapter 2. Subsequently, the various capacitor types are considered in
detail in Chapter 3.
Capacitor types
Polarity:
Capacitor type:
non-polar
capacitors
Film
capacitors
Ceramic
capacitors
Electrolytic
capacitors
Super
capacitors
Capacitors
with fixed
capacitance
polar
capacitors
+
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