Input cap ripple current calculation

[Fluorescence]

Hello,

I just took apart a 15W CFL (240V 50Hz) and did a test on the DC bus just after the diode bridge. (This CFL has a mini , 2 transistor SMPS inside it to power the bulb)

The Capacitor just after the diode bridge has 110V of (100Hz) ripple on it (it goes from 220V to 330V)

I am trying to calculate the ripple current in the electrolytic capacitor occurring just after the diode bridge.

Here is a representation of the capcitors voltage.....

Here is a representation of the capacitors current.....

Here is a representation of the voltage and current of this cap from a simulation of a similar circuit....
(cap voltage in green, cap current in blue)

...................

Do you believe that the only way to calculate the RMS capacitor ripple current is to...

1. Calculate the Mean of the square of the capacitor charging current (by integrating i(t)^2 (charging current alone) over one half-period and dividing by pi)

2. Calculate the mean of the square of the discharging current alone. (by integrating the square of that switching current over one half mains period and dividing by pi)

3. Find the Mean of the values of (1) and (2).

4. Take the root of the value in (3).

....Any thoughts on if this is a correct method or not much appreciated.

 

[7anoter4]

hi Fluorescence
I cannot see your images since this it is not the right way to display them.The right way is as follows:

But first of all you have to reduce the image to 50% at least!
Best Regards

 

[hacksaw]

for what its worth the images show up just fine for me