Why Raise Capacitance in Smoothing Caps?

[MITEE]

I watched a vid the other day and the guy changed the main smoothing caps from 6800uf to 10,000uf.

What is the reasoning for doing this, and what are the instances in which you wouldn't do such a thing?

 

[Martaine2005]

One reason could be to further smooth the ripple. Especially under load.


Martin

 

[Bluejets]

..........voltage ripple

 

[CircutScoper]

One reason could be to further smooth the ripple. Especially under load.


Martin

Yeah. Ripple. Smoooooth!

 

[Martaine2005]

 

[danadak]

If you raise cap values :

1) Time to discharge when powering off increased.
2) Surge current on power up increase. More stress for other components.
3) Ramp up time at power on increased.


Regards, Dana.

 

[CircutScoper]

View attachment 55353

Yup. Vpp-ripple = Load / C / F / 2
Load in Amps, C in Farads, F = mains frequency in Hz

 

[bertus]

Hello,

Have a look at this picture:


More info in the attached PDF.

Bertus

 

[CircutScoper]

Hello,

Have a look at this picture:
View attachment 55360

More info in the attached PDF.

Bertus

Another ploy is to minimize the effect of ripple by making the load more tolerant of it. E.g., by using a voltage regulator with a lower drop-out voltage.

 

[Bluejets]

Then there are inductors for current ripple......