Re: calculating ripple

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz>

Hi Ken
Q= CV = IT
So V = IT/C
Where V = ripple
C= Capacitance Farads
I = current drawn in amps
T = 1/120sec (in this case)
Best
Ted L in NZ
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, August 22, 2002 4:39 PM
Subject: calculating ripple


> Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<tesla-at-lists.symmetric-dot-net>
>
> How do some people here calculate ripple on a capacitor being charged at
> 120Hz from a bridge rectifier and a load of x amps? So far every place
I've
> looked has a different formula, and none have consistent answers.
>
> - the Rado Shack "Building Power Supplies" book suggests
>
>    Vrms = 2.4 I/C
>
> where Vrms = ripple volts
> 2.4 comes from apparently nowhere
> I = current in mA
> C = capacitance in uF
>
> - this link on audio amplifier design says
>  http://sound.westhost-dot-com/power-supplies.htm#capacitor-value
>
> which comes to a different answer yet again.
>
> - another link has something similar
> http://www.mitedu.freeserve.co.uk/Circuits/Power/unreg.htm
>
> - and one more
> http://my.integritynet-dot-com.au/purdic/power1.html
>
> and the botton of the page here
> http://www.signaltransfer.freeuk-dot-com/powerout.htm
>
> So, what should I use, and where do these strange numbers like the "factor
> of 7" for 60Hz and "2.4" come from?
>
> KEN
>
>
>
>