Factors to Consider While Selecting the Right Capacitor

Capacitors are one of the basic electronic components that find use in a range of applications. It is true that all capacitors are designed to perform the same fundamental function, which is to effectively store the electrical energy, in order to give it back to the circuit as and when needed. However, when you buy capacitors or capacitors plastic film, you must take into account a number of factors in order to obtain the right capacitor that would perfectly suit your needs.

Different types of capacitors are available with online sellers, namely ceramic, non-polarized, electrolytic, and many more. Given below is a list of practical factors to consider while making your purchase.

Value

Capacitors are available in various sizes, the most common range being 1pF to 100,000mF. However, you must know that all types of capacitors are not available in all values. It depends on what kind of capacitor you are buying; you should check whether it is available in the required value.

Working Voltage

The thumb rule for the efficient use of a capacitor is that you should buy capacitors that possess higher working voltage in comparison to the circuit for which it will be used. This is an extremely crucial thing to consider, especially when you are using high value electrolytic capacitors in power supply circuits. Make sure that the working voltage of the capacitor exceeds the circuit’s peak working voltage by at least 20%.

Polarization

Polarized capacitors have distinctly marked positive as well as negative terminals. You should never use them by connecting in the incorrect way. Also, refrain from incorporating these capacitors in circuits where there are chances that the voltage will reverse polarity. Wrong connection may lead to dangerous consequences and in some cases the capacitors may even explode.

Temperature Coefficient

This implies how the capacitance varies with temperature. The temperature coefficient is popularly known as ‘Tempco’, and is majorly expressed in parts per million per degree Celsius, in the form of a variation or percentage. The temperature coefficient of a capacitor may be negative or positive, which means that the value might decrease or increase with temperature. There are also NPO (Negative Positive Offset) capacitors, which are mainly used in tuned circuits and radios.

Tolerance

Certain circuits, such as those used in oscillators might call for a high precision capacitor, so keep in mind the same when you buy capacitors. If the tolerance of the capacitor does not match the one mentioned in the parts list, it might not function properly and you will not get the desired results.

Leakage Current

In case of certain capacitors, the dielectric has a leakage current flowing through it, and as a result, the capacitor may not retain its charge for a long period of time. If you want to buy capacitors for timing circuits, it is good to opt for such low leakage types.

By choosing the right capacitor through taking note of these factors, you can make your application run smoothly. So, next time you are buying a capacitor, choose it wisely so that it lasts long and there are no issues.