Linear Power Supplies..why 2 or 3 smoothing caps ??

Thread Starter

ranatungawk

Joined Oct 30, 2008
162
On Linear Power Supplies, i have seen two or three 1000uf capacitors are used parallely (just after the bridge rectifier) as smoothing caps instead of using one 3000uf capacitor. Has it been designed so purposelessly ? or no special reason (are 3 x 1000uf slimier to one 3000uf)?
 

wayneh

Joined Sep 9, 2010
16,102
In other words, there's no secret advantage to multiple caps in parallel, versus a single cap. The equivalent series resistance and heat dissipation would be very slightly better for multiple caps, so it's remotely possible the 1,000µF caps were a cheaper or easier solution than choosing a single cap that was properly rated for the job.

I expected from the title that this question was going to be about using different types and values of caps in parallel, such as a big electrolytic and a 0.1µF ceramic. This is about filtering different frequencies more effectively. Electrolytics are too slow for high frequency filtering.
 
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