Filter Element
A filter element is a circuit component or part that classifies electrical signals according to their frequency. The circuit that extracts a signal containing specific frequency components from the input electrical signals is called an active filter, and its main filter elements are active elements such as resistors, capacitors and amplifier elements (vacuum tube, transistor, OA amplifier, etc.). In contrast, a circuit consisting only of passive elements that are used when selecting high voltage or current signals is called a passive filter, and its main filter elements are resistors, capacitors, coils and transformers. Filter elements can be purchased as separate parts, but they are also available in a package of the elements required for composing the filter. In either case, it is important to select the appropriate part after confirming the filter application and specifications.