capacitor circuit doubt

Hi all,

i have attached a circuit diagram which contains a capacitor in parallel to a voltage source, is the configuration possible? i.e. does the capacitor gets charged? capacitor gets charged by the voltage or the current flowing through it? a resistor is required to charge the capacitor?

thanks in advance,
regards,
satya

Dear satya
Hi
Your circuit is correct . but if you add a series resistance with your capacitor , thus you can control time constant ! it means you'll be able to set your desired time as occupying time of your capacitor . ( thus it will charge slower )
and about current and voltage :
Your capacitor will have a large value of inrush current at transient time , and at t=0+ ( a bit after start time ) it will try to be full of charge by an exponential function
i hope i understood what you mean correctly !
Best Wishes
Goldsmith

hi,
thank you very much for the reply. so i tried to write the equation i get the current equation as

I = V/j*2*Pi*f*c, since f is 0 for dc it results in infinite current. Am i correct in this? is it possible to measure this current? and on what factors does it depend on i.e. the magnitude?

thanks in advance,
regards,
satya

Yes, you in theory will get infinite current at switch-on. In practice the current will be limited by the voltage source and the equivalent series resistance of the capacitor.

Keith

How will capacitor discharge? Shouldn't we add ground terminal too in circuit.

A ground terminal isn't necessary for a discussion about charging a capacitor as long as there is a path for current flow, which there is.

Keith

theoretically connecting an IDEAL VOLTAGE SOURCE to an IDEAL CAPACITOR in parallel leads to infinite current , that means it will get charged in time=0

practically every voltage source has a series resistance and same with the capacitor , so it will still be a high current but will take some time to charge the capacitor

Adding a resistance varies the charging time Tc as per requirement as well as discharge time Td

in your circuit the capacitor will never get discharged !!!

hope everything is clear now

:pH said:

theoretically connecting an IDEAL VOLTAGE SOURCE to an IDEAL CAPACITOR in parallel leads to infinite current , that means it will get charged in time=0

practically every voltage source has a series resistance and same with the capacitor , so it will still be a high current but will take some time to charge the capacitor

Adding a resistance varies the charging time Tc as per requirement as well as discharge time Td

in your circuit the capacitor will never get discharged !!!

hope everything is clear now

Click to expand...

This is what i was referring to in my above post. Got the answer. Thnks dude.

electronic_satya,

i have attached a circuit diagram which contains a capacitor in parallel to a voltage source, is the configuration possible?

Click to expand...

In theory yes, in practice, no. By the way, the cap is in series with the voltage source. The current in the voltage source and cap leads is the same.

i.e. does the capacitor gets charged?

Click to expand...

No, it gets energized. It has the same amount of net charge after the voltage is applied as it did before the voltage was applied, namely zero. But its energy after the voltage is applied is ½CV²

capacitor gets charged by the voltage or the current flowing through it?

Click to expand...

No current exists through a capacitor. Charge accumulates on one plate and depletes on the opposite plate.

a resistor is required to charge the capacitor?

Click to expand...

Theoretically no, but in the real world, resistance is always present.

P.S. Sentences in English always begin with a capital letter.

Ratch