Rectifier filter

Thread Starter

Kaiser Ed Bayawa

Joined Mar 19, 2015
64
I am having a problem with my power suppy. The 12v transformer, I used bridge rectifier and a capacitor 2200uF filter.
But still the output is not smooth.
Do you have any idea about this filter?
 

ronv

Joined Nov 12, 2008
3,770
I am having a problem with my power suppy. The 12v transformer, I used bridge rectifier and a capacitor 2200uF filter.
But still the output is not smooth.
Do you have any idea about this filter?
It should work, but the ripple will depend on how much current you draw from the supply.
 

MrAl

Joined Jun 17, 2014
6,973
I am having a problem with my power suppy. The 12v transformer, I used bridge rectifier and a capacitor 2200uF filter.
But still the output is not smooth.
Do you have any idea about this filter?
Hi,

Add more caps in parallel, that makes it smoother.
To get very smooth you need a voltage regulator.
 

wayneh

Joined Sep 9, 2010
16,162
You've gotten two solutions, more capacitance or a voltage regulator. There may be other solutions if you give more details about the rating of the transformer and the load you need to power.
 

AnalogKid

Joined Aug 1, 2013
8,258
With the schematic you posted, the output never will be "smooth". Ever. It always will have some ripple. Increasing the size of the capacitor will decrease the ripple amplitude, but it will not - cannot - eliminate it.

ak
 

ErnieM

Joined Apr 24, 2011
8,011
Define smooth = how much peak to peak ripple can you allow?

If that is zero you need a voltage regulator. If some number tell us what The lad R is and we can show you how to calculate how much capacitance you need.
 

alfacliff

Joined Dec 13, 2013
2,458
your circuit is of a simple "brute force " filter. more capacitance is need for this type. even with a regulator, more filter cap would be needed to prevent the regulator fromj dropping out under load.
 

ErnieM

Joined Apr 24, 2011
8,011
For a 2200uF cap, 60 cycle full Wave bridge with the full load of 0.75ma one should expect on the order of 2.8 volts peak to peak of ripple.

Doubling your cap halves that number. Ten times the cap drives it down to just 0.28 V p-p.

(edited to add spec'd load current)
 
Last edited:

wayneh

Joined Sep 9, 2010
16,162
Those depend on the load. No load, (almost) no ripple. Loading at double the rating, big ripple, and the cap does little except increase the total load.
 
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