ripple current measurement

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hi ,
I want to calculate the ripple current flowing in a given circuit through a capacitor.
For example the load requires 40V@10A and I am using a 10000uf capcitor what will be my ripple current through the capacitor.
I calculated ripple voltage as = I/2F X C so the ripple voltage comes to 10V from here how do i calculate the ripple current..........??????????


regards
Sekhar
 
You need to know the charge and discharge times as a proportion of the mains cycle time. As a reasonable first guess, the cap is charging for 20% of the time and discharging for 80%.

Assuming that 10A output current flows all the time then the charging current will be 50A. I'm not sure whether the ripple current is defined as the average capacitor current over time - if so then its going to be (40A * 0.2) + (10A * 0.8) = 16A. The heating effect within the capacitor though is going to be proportional to the mean squared current which is considerably greater than the average.
 
lets say the ripple voltage is 10V as shown in the picture how will i get to ripple current from ripple voltage





regards
sekhar
 

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sekhar said:
if u will help me to learn
Is your calculus and trigonometry up to the required level of understanding? If so, you can probably do it yourself. If not, we can't offer help beyond that already given unless you want DIYaudio to become a mathematics class for beginners.

NB Calculating the exact current of a charging pulse is non-trivial. Most people who know enough (in principle) to know how to do it will know enough (in practice) to use a simulation such as Spice or PSUD2.
 
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