The choice of capacitor for radio and other electronic devices must be correct. The reliable operation of the structure and its safety depend on this. Before installing the element in the circuit of the circuit, study the necessary literature.
Capacitor selection recommendations
Radio amateurs use aluminum, tantalum, ceramic capacitors and many others. Its reliability during operation depends on the correct choice of a capacitor, since it must be used in such operating modes that do not exceed the specified conditions. To do this, it is necessary to determine the values of the nominal parameters and their permissible changes during operation, possible modes and electrical loads, design, indicators of reliability and durability, installation options, dimensions and weight.
Practice shows that the permissible voltage indicated on its body should not be less than on the electrical circuit. You can choose more by 20-30%. The capacity can be used within + -10%, but it is better to take it no less than on the electrical circuit.
If capacitors must be in the power supply circuit, bypass the RF (high frequencies), then it is better to use ceramic. If they must be installed in a frequency setting stage, then it is better to take them with a small TKE (temperature coefficient of capacitance) so that there is no frequency drift. In all cases, capacitors should be used at lower loads and light duty (compared to the maximum allowable).
Additional information on capacitor selection
The installation and fastening performed must provide the required mechanical strength, excellent electrical contact and the absence of resonance phenomena. Their devices (for fastening) must not damage the body and protective coatings, as well as worsen the conditions for heat dissipation. It is never necessary to use capacitors of dubious origin (for example, electrolytic ones, made of poor quality, can explode). It is necessary to pay attention to the ease of installation and the presence of protection of the output contacts from accidental closure.
Radio amateurs choose capacitors according to their capacitances and operating voltages. But there are other characteristics to look out for. Capacitors do not yet have ideal parameters, so they have such properties as ESR (Effective Series Resistance) - equivalent series resistance and ESI (Effective Series Inductance) - equivalent series inductance. Their capacity is influenced by temperature, voltage, mechanical stress. With the wrong choice of capacitor, increased current consumption and increased noise level, unstable operation of the entire structure may appear.
