Ultimately, capacitors store charge. There are a lot of things you do with capacitors.
Capacitors go great in electronic filters -- to filter out frequencies you don't want.
A low pass filter -- low frequencies show up at the output, high frequencies are cut out.
A high pass filter -- high frequencies show up at the output, low frequencies are cut out.
Combined with an inductor, they make a resonator circuit that can cut off only a narrow range of frequencies or even greatly amplify a single frequency.
A band-pass filter that allows only specific frequencies to pass.
Capacitors are used often to help stabilize a power supply -- since they form a shunt to AC but leave DC alone, if you want a stable power supply you will probably use capacitors to shunt off noise, leaving a nice steady DC voltage at the output.
The transient response of an RC circuit is also incredibly useful for timing.
Transient response of an RC circuit
Since it takes a predictable amount of time to reach a specific voltage, it can be used to time electronic switching.
The time on and time off are set by the capacitor and two resistors in the timing circuit shown above.
Again, since they store charge, they can be used as part of a system to convert AC to DC.
Without using the capacitor, instead of being a rippled DC, it looks like a sine wave with the bottom part flipped up.
That's just a small sampling. They do a lot of things, including differentiation and integration (calculus functions), decouple biased circuits, shift voltage phase to compensate power, and hold charge for temporary use.
And then there are all the things that you don't want capacitance for, but have to deal with anyway because capacitance is a physical thing, not something that only exists on devices that specify it. Like signal cross-talk, messing with input and output impedance, adding noise, being sensitive to acoustic vibrations, etc.
If you want to know what specific capacitors are for in a circuit, please ask and I might be able to point it out.
By : Jacob-VanWagoner
Capacitors go great in electronic filters -- to filter out frequencies you don't want.
Combined with an inductor, they make a resonator circuit that can cut off only a narrow range of frequencies or even greatly amplify a single frequency.
Capacitors are used often to help stabilize a power supply -- since they form a shunt to AC but leave DC alone, if you want a stable power supply you will probably use capacitors to shunt off noise, leaving a nice steady DC voltage at the output.
The transient response of an RC circuit is also incredibly useful for timing.
Since it takes a predictable amount of time to reach a specific voltage, it can be used to time electronic switching.
Again, since they store charge, they can be used as part of a system to convert AC to DC.
That's just a small sampling. They do a lot of things, including differentiation and integration (calculus functions), decouple biased circuits, shift voltage phase to compensate power, and hold charge for temporary use.
And then there are all the things that you don't want capacitance for, but have to deal with anyway because capacitance is a physical thing, not something that only exists on devices that specify it. Like signal cross-talk, messing with input and output impedance, adding noise, being sensitive to acoustic vibrations, etc.
If you want to know what specific capacitors are for in a circuit, please ask and I might be able to point it out.
By : Jacob-VanWagoner
can you please explain how capacitor does this
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