DrNomis_44
22-12-2016, 04:09 PM
Hi everyone,
Thought I would do another mini-tutorial thread, but this time it is all about Capacitors.
Okay, so what is a Capacitor?, a Capacitor is an electronic component made up of two conductors which are separated by an insulator, the insulator can be made using a variety of materials which do not allow the flow of an electrical-current through them, these materials are commonly called insulators, one type of insulating material used in early capacitors is waxed paper, the only trouble with using waxed paper as an insulator is that it tends to degrade and go leaky over time, that is, it tends to let a small amount of electrical-current flow through it from one conductor to the other, ideally there should be absolutely no current-flow whatsoever, later capacitors used materials, like paper in oil,mica, ceramic, polystyrene, polyethylene, and polypropylene, insulators such as ceramic, polystyrene, polyethylene, and polypropylene tend to exhibit much better insulating electrical characteristics than waxed paper, paper in oil tends to be used in Capacitors intended for High Voltage applications, some Capacitors are made using Tantalum as the insulating material too, Mylar is another material that is used in Capacitors as well.
One of the most important electrical characteristics of an insulating material in a Capacitor is what's called it's working voltage, this is simply how much voltage the insulating material can withstand before it becomes punctured and then lets a small amount of current flow through it.
I have seen Capacitors that use ceramic as an insulating material, rated at up to 3kV working-voltage, that means that the ceramic insulator can withstand up to 3,000 Volts before puncturing, the working-voltage rating of a Capacitor is important because you do not want the Capacitor to fail under normal circuit operating-conditions, what you want to do is have the working-voltage of a capacitor to be higher than the highest expected voltage in a circuit, so say for example that you are building an FX pedal for your guitar and you know that it is going to be powered by a 9V battery, you can safely get away with using a Capacitor with a working-voltage rating anywhere from 16V to something like 63V, a working voltage rating of 1V is cutting it a bit close, and a working voltage rating of 6.3V is too low and there's a risk of the Capacitor literally exploding, I have actually had that happen to me at least a couple of times.
The conductors in the Capacitor can be made from a variety of conducting materials, like for example Silver, Copper, and Aluminium, to name a few, some Audiophile-Grade Capacitors are made using Copper Foil, I'm not sure what the insulating material is though.
Capacitors come in two basic types, Polarized, and Non-Polarized, Polarized Capacitors must be connected up in a circuit the correct way for them to operate correctly, whereas Non-Polarized Capacitors can be connected up either way and will still function correctly, if you connect up a Polarized Cap in a circuit incorrectly the Capacitor could explode.
Small capacitors are marked in values from about 1pF (pico-Farad), to something like .820uF or 820nF (nano-Farads)
The basic unit of Capacitance is called the Farad, which was named after an English Scientist/Physicist Michael Faraday, now, the Farad is actually a very big value of Capacitance, much bigger than what is used in most electronic circuits, but Capacitors with a value of 1 Farad actually do exist.
Here's a scale to show exactly how big a value 1 Farad is, considering that you will mostly encounter values in the uF (micro-Farads), nF (nano-Farads), and pF (pico-Farads):
1 Farad = 1000 mili-Farads.
1 mili-Farad = 1000 micro-Farad.
1 micro-Farad = 1000 nano-Farad.
1 nano-Farad = 1000 pico-Farad.
1 pico-Farad = 1000 femto-Farad.
Capacitors do one of two jobs in an Electronic circuit, they store energy, or, they block the flow of D.C. (Direct Current), and allow A.C. (Alternating Current) to flow, the tone Cap in a guitar is an example of a Capacitor used to allow A.C. to flow to circuit-ground, it is normally connected to a pot (variable-resistor) which gives us a way to control how much A.C. is allowed to flow to circuit-ground.
Thought I would do another mini-tutorial thread, but this time it is all about Capacitors.
Okay, so what is a Capacitor?, a Capacitor is an electronic component made up of two conductors which are separated by an insulator, the insulator can be made using a variety of materials which do not allow the flow of an electrical-current through them, these materials are commonly called insulators, one type of insulating material used in early capacitors is waxed paper, the only trouble with using waxed paper as an insulator is that it tends to degrade and go leaky over time, that is, it tends to let a small amount of electrical-current flow through it from one conductor to the other, ideally there should be absolutely no current-flow whatsoever, later capacitors used materials, like paper in oil,mica, ceramic, polystyrene, polyethylene, and polypropylene, insulators such as ceramic, polystyrene, polyethylene, and polypropylene tend to exhibit much better insulating electrical characteristics than waxed paper, paper in oil tends to be used in Capacitors intended for High Voltage applications, some Capacitors are made using Tantalum as the insulating material too, Mylar is another material that is used in Capacitors as well.
One of the most important electrical characteristics of an insulating material in a Capacitor is what's called it's working voltage, this is simply how much voltage the insulating material can withstand before it becomes punctured and then lets a small amount of current flow through it.
I have seen Capacitors that use ceramic as an insulating material, rated at up to 3kV working-voltage, that means that the ceramic insulator can withstand up to 3,000 Volts before puncturing, the working-voltage rating of a Capacitor is important because you do not want the Capacitor to fail under normal circuit operating-conditions, what you want to do is have the working-voltage of a capacitor to be higher than the highest expected voltage in a circuit, so say for example that you are building an FX pedal for your guitar and you know that it is going to be powered by a 9V battery, you can safely get away with using a Capacitor with a working-voltage rating anywhere from 16V to something like 63V, a working voltage rating of 1V is cutting it a bit close, and a working voltage rating of 6.3V is too low and there's a risk of the Capacitor literally exploding, I have actually had that happen to me at least a couple of times.
The conductors in the Capacitor can be made from a variety of conducting materials, like for example Silver, Copper, and Aluminium, to name a few, some Audiophile-Grade Capacitors are made using Copper Foil, I'm not sure what the insulating material is though.
Capacitors come in two basic types, Polarized, and Non-Polarized, Polarized Capacitors must be connected up in a circuit the correct way for them to operate correctly, whereas Non-Polarized Capacitors can be connected up either way and will still function correctly, if you connect up a Polarized Cap in a circuit incorrectly the Capacitor could explode.
Small capacitors are marked in values from about 1pF (pico-Farad), to something like .820uF or 820nF (nano-Farads)
The basic unit of Capacitance is called the Farad, which was named after an English Scientist/Physicist Michael Faraday, now, the Farad is actually a very big value of Capacitance, much bigger than what is used in most electronic circuits, but Capacitors with a value of 1 Farad actually do exist.
Here's a scale to show exactly how big a value 1 Farad is, considering that you will mostly encounter values in the uF (micro-Farads), nF (nano-Farads), and pF (pico-Farads):
1 Farad = 1000 mili-Farads.
1 mili-Farad = 1000 micro-Farad.
1 micro-Farad = 1000 nano-Farad.
1 nano-Farad = 1000 pico-Farad.
1 pico-Farad = 1000 femto-Farad.
Capacitors do one of two jobs in an Electronic circuit, they store energy, or, they block the flow of D.C. (Direct Current), and allow A.C. (Alternating Current) to flow, the tone Cap in a guitar is an example of a Capacitor used to allow A.C. to flow to circuit-ground, it is normally connected to a pot (variable-resistor) which gives us a way to control how much A.C. is allowed to flow to circuit-ground.