What is the role of of a capacitor in circuits?

What is the role of of a capacitor in a practical circuit? In general, I know about capacitors, but I don't know in what point of a circuit I should use them, and what is their role. Does anyone have a book with practical usage of capacitors, very well explained? Thank you!

Re: about capacitors

There are some good books here. From Basic to advanced. It would be very difficult to try and explain all the possible uses of capacitance. DC, AC, pulsed, Timing etc... it just keeps going. Hope you find something here.

h**p://www.giuciao.com/books/sorted.php?by=Engineering&ord=id


good luck

dfullmer

about capacitors

decoupling bypassing compansation SC time-constant filters integrators diffrentiators

Re: about capacitors

In this website:
**broken link removed**
you will find description of common capacitor types together with their applications .. All what it takes is 5 minutes of reading ..

Regards,
IanP

Re: about capacitors

a capacitor can be used as a decouple capacitor(by pass high frequence);

a couple device to block dc voltage; as part of a oscilator.

best regards

impakt said:

What is the role of of a capacitor in a practical circuit? In general, I know about capacitors, but I don't know in what point of a circuit I should use them, and what is their role. Does anyone have a book with practical usage of capacitors, very well explained? Thank you!

Click to expand...

about capacitors

capacitors presents every where in electronics.....we realise it in all kind of devices....it determines steady state response..shape of output(diff and integrate)....

Re: about capacitors

well capacitors have a lot of use like bypassing, power supply noise rejection and in some cases even the replacement of an inductor using gyrator etc... new uses are often being found so you can understand them only by analysing circuits...

Re: about capacitors

Capacitors can be used to smooth out supply current, example absorbing spikes. Usually used because of unstable supply to the device (noise).

It is also more commonly used to control oscillation frequency. Example frequency of a phase shift oscillator or the frequency of a micro-controller.

Rf circuits also used capacitors as to determine frequency of the wave generated or filtered.

In some application, capacitors are also used to step up voltage.

Re: about capacitors

Hello again,
about capacitors: can anyone explain me what is the purpose of C1, C2 and C3 in the attached figure?
Thank you!

Re: about capacitors

If it's useful then press help plz

Re: about capacitors

a_tek7 said:

If it's useful then press help plz

Click to expand...

In theory I know the purpose of a capacitor...the practice is killing me. So, thank you for your document, but I already knew that.

Re: about capacitors

impakt said:

Hello again,
about capacitors: can anyone explain me what is the purpose of C1, C2 and C3 in the attached figure?
Thank you!

Click to expand...

So?

Re: about capacitors



I think by the figure, they are use for providing constant voltage as a DC voltage is applied on them.Look at the right RED circle, R29,R28 and C1 are connected with +13V.If there's no capacitor C1.Voltage might get to around +13.5 or +14 or +15 or maybe +12.6 +12.2V.It depends what kind of noise might present or maybe it's also possible that there's no variation at all, because your power supply of +13V is very good.So you may not need any capacitor at all, but there are times when your very own component some times produces noise and cause the voltage levels to change.So C1 is attached over there because you want only +13V and you don't want it to change slightly.Remember capacitor always opposes the Rate of change(dv/dt), Capacitor don't like changing voltage.So C1's job is to stick the voltage level to +13V.Now suppose you change the power supply to +14V, so at first your capacitor as is stick +13V will try not to change it to +14V it will to oppose you, but as you have the control...you can change the voltage supply to +14V.When the supply comes to +14V your capacitor will be set at +14V, so it will be set on +14V and it will not want +14V to increase or decrease.

Right RED circle components are fixed at +13V and the Left RED circle components are fixed at +13V, because of a zener diode D5.Zener diode is functioning as a voltage regulator and converting +13V to +5V.So you have C2 and C3 capacitor which are helping it to stick on this voltage level.If you get a little variation in voltage.

Added after 37 minutes:



For example in above figure, you have two culprits running on different vehicle after robbing a bank.Above one has got a train and the other one is running off on a bicycle.Both are moving at 13km/hr and two POLICE car wants to stop them.Since the above the guy is running off in train have capacitors connected on them(Capacitor are one which dislikes the rate of change of voltage(dv/dt) so as train is massive and has inertia, it's very difficult a POLICE car to stop a massive train.So after hitting the POLICE car, the car would be boomed and will break into different pieces, the train speed will remain constant at +13V it will not drop, because we have lot of capacitors connected on it, which are helping to maintain 13km/hr or +13V

The bicycle has no mass as compared to a train.Bicycle is very light weight.So a POLICE car can very easily stop the bicycle.When a bicycle will hit the car, the will get a dent on it's body, but bicycle speed will drop to 0V or 0km/hr.Although you can see a small blue capacitor, that's a parasitic capacitor.This capacitance will try to maintain the bicycle speed to +13V, but this one is very small.If you find some capacitance at a point in circuit, but even there's no capacitor attach, that's called as parasitic capacitance.Capacitance of a magical capacitor, which you can't see.

Re: about capacitors

The basic function of the capacitor is to store electrostatic energy between two parallel plate conductors. In general this stored energy cannot be stored permanently. It can be used to filter the DC components in the circuits.
Applications are like Low pass filters, High pass filters, band pass filters and band rejection filters.
More used in Oscillator circuits.
There are many many applications you can find in day to day life.
Please refer some basic electrical engineering text books.

Regards,
N.Muralidhara

Re: about capacitors

Hi Friends,

Put in one sentence....."In a capacitor voltage leads current by 90deg" and like wise "in an inductor current leads voltage by 90deg".


So these two components are used whenever phase lead-or-lag is neccessary.

Sai

Re: about capacitors

umery2k75 said:

For example in above figure, you have two culprits running on different vehicle after robbing a bank.Above one has got a train and the other one is running off on a bicycle.Both are moving at 13km/hr and two POLICE car wants to stop them.Since the above the guy is running off in train have capacitors connected on them(Capacitor are one which dislikes the rate of change of voltage(dv/dt) so as train is massive and has inertia, it's very difficult a POLICE car to stop a massive train.So after hitting the POLICE car, the car would be boomed and will break into different pieces, the train speed will remain constant at +13V it will not drop, because we have lot of capacitors connected on it, which are helping to maintain 13km/hr or +13V

The bicycle has no mass as compared to a train.Bicycle is very light weight.So a POLICE car can very easily stop the bicycle.When a bicycle will hit the car, the will get a dent on it's body, but bicycle speed will drop to 0V or 0km/hr.Although you can see a small blue capacitor, that's a parasitic capacitor.This capacitance will try to maintain the bicycle speed to +13V, but this one is very small.If you find some capacitance at a point in circuit, but even there's no capacitor attach, that's called as parasitic capacitance.Capacitance of a magical capacitor, which you can't see.

Click to expand...

Thank you all, nice example...
One question: who is the police car in a real circuit?