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Capacitorvery basic questionsby vig
Tags: capacitor waveform 
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#1
Apr2812, 08:11 AM

P: 18

Ive already gone through many posts on working of capacitors...but if i consider a very simple circuit...say i connect a function generator (which generates a sawtooth wave) across a capacitor...(no resistance in series)...and i measure voltage accross the capacitor, what will be the waveform like?..one theory says that since the capacitor is connected in parallel to the function generator, i must get the same sawtooth waveform..however, voltage across capacitor can not change abruptly and so i should be getting a smooth waveform across it..it would be great if someone can clear things out...



#2
Apr2812, 08:17 AM

P: 2,179

If it is an ideal voltage generator, and an ideal capacitor, the voltage generator will supply the infinite current necessary to get an abrupt change in the voltage across the capacitor. In practice, both the capacitor and the voltage generator have some resistance and some inductance, and the voltage generator is limited in the amount of current it can supply. These nonideal elements will determine exactly what the waveform looks like.



#3
Apr2812, 12:24 PM

P: 18

'voltage generator will supply the infinite current necessary to get an abrupt change in the voltage across the capacitor'...could u pls elaborate on this?..and considering the most ideal situation, the waveform across a capacitor would show sharp peaks??...and if a resistor is connected in series, and the function generator can still source infinite current (say), the waveform would remain the same?



#4
Apr2812, 03:57 PM

Mentor
P: 12,071

Capacitorvery basic questions



#5
May212, 11:10 AM

P: 18




#6
May212, 04:37 PM

P: 2,179




#7
May212, 06:01 PM

Mentor
P: 12,071

If we spent more time thinking about how real devices behave, we might come up with other factors too. 


#8
May212, 11:34 PM

P: 18




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