A capacitor is a device that stores electrical energy in an electric field. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit. Axial lead capacitor shown to the right.
Simple Definition: A capacitor is used to divert the flow of frequencies in a guitar pedal. They can cut out the low frequencies and only let the highs through.
Capacitor values are measured in Farads, and fractions of a Farad: Picofarad pF (trillionth), Nanofarad nF (billionth), and Microfarad uF (millionth)
Basically most capacitors come in radial and axial form which means the legs or leads either come out of the sides or the bottom as you can see! Most GPCB boards are designed for radial capacitors, which take up less real-estate on the PCB, and provide a more professional looking appearance to the project. In most cases you can use axial if you do not have radial, but it’s not advised because the PCB was not designed for them and therefore, it will look sloppy and unprofessional.
Today, axial capacitors are used mainly for Vero board or amplifier builds and where longer legs are sometimes needed for a better/easier connection. Radial lead capacitor shown to the left.
Above images are used to depict a capacitor on a schematic. Some schematics the creator will list the item number or the size of the item. In the cases above, a 0.1nF and 10uF capacitors are shown. A non-polarized capacitor can be connected any way in a circuit. A polarized capacitor can only be connected one way in a circuit.
Capacitor Types:
Ceramic Capacitors: The ceramic disc as well as the polyester capacitors are non polarized. Measured in pF (Picofarad) and lower nF (Nanofarad) for small / medium values Almost all have a number code printed on the body e.g. 101 = 10 + 1 zero = 100 pF
Poly Capacitors: A capacitor that uses a plastic polymer, such as polystyrene or polyester, as part of its operational components is commonly called a poly capacitor. Since the introduction of poly capacitors in the late 1950s, improvements in plastics have allowed them to evolve alongside electronics. Measured in nF (NanoFarad.) for medium values and lower uF for non polarized requirements from time to time – again come in axial or radial form pin spacing should be 5mm.
Metal Film Capacitor: In this type of film capacitor the plastic film has a very thin layer of metal deposited onto the film. The thin metal layer is typically only 0.02 to 0.1µm thick. This is vacuum deposited onto the plastic film. Measured in nF (NanoFarad.) for medium values and lower uF for non polarized requirements from time to time – again come in axial or radial form pin spacing should be 5mm.
Box Capacitor: 5mm pitch metallised polyester capacitors ideal for situations where a high packing density is required. Measured in nF (NanoFarad.) for medium values and lower uF for non polarized requirements from time to time – again come in axial or radial form pin spacing should be 5mm.
Electrolytic Capacitor: An electrolytic capacitor (occasionally abbreviated e-cap) is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor. A solid, liquid, or gel electrolyte covers the surface of this oxide layer, serving as the cathode or negative plate of the capacitor. Due to their very thin dielectric oxide layer and enlarged anode surface, electrolytic capacitors have a much higher capacitance-voltage (CV) product per unit volume than ceramic capacitors or film capacitors, and so can have large capacitance values. There are three families of electrolytic capacitor: aluminum electrolytic capacitors, tantalum electrolytic capacitors, and niobium electrolytic capacitors. Measured in uF microfarad for larger values polarized with small minus signs down the negative side and the positive lead is usually longer.
Tantalum Capacitor: A tantalum electrolytic capacitor is an electrolytic capacitor, a passive component of electronic circuits. It consists of a pellet of porous tantalum metal as an anode, covered by an insulating oxide layer that forms the dielectric, surrounded by liquid or solid electrolyte as a cathode.Electrolytic positive side identified by longer lead and + sign sometimes with a vertical line. It is very important to get the orientation right the first time with these, as they can damage your pedal.
Tropical Fish Capacitor: Polyester film type cap. They sound excellent in a Stratocaster, offering a very fat tone that doesn’t turn into mud with overdrive or distortion. Compared to the Sprague Orange Drop caps, these have more mid-range and less high-end sizzle. If you have a thin-sounding Stratocaster.