[AMPS] Alminum Capacitor

[John Fielding]

No sir - off line switchers need large input smoothing caps for 2 reasons.

1.	To hold up the supply for several dropped mains cycles.
2.	To reduce the ripple on the raw DC to prevent sub-harmonic operation.

These types of caps have low esr and can handle oodles of ripple current at 50kHz and
upwards.  Don't forget that although the mains supply produces a 100Hz/120Hz ripple
component, the switching device draws very large peaks of current at the switching
frequency.

John	ZS5JF


----------
> From: measures <measures@vcnet.com>
> To: ohashi <ohashi@ny.airnet.ne.jp>; AMPS <amps@contesting.com>
> Subject: Re: [AMPS] Alminum Capacitor
> Date: 15 September 1999 06:20
> 
> 
> >
> >Greetings from Japan !
> >
> >I got 8 pcs of Aluminum Capacitors (Not used JUNK) at
> >Japanese HAM FAIR last month.
> >
> >The printing on the capacitor is as follows;
> >
> >560uF 450V, 105 degree C, MKH
> >Nippon Chemicon
> >
> >Surprisingly the size is very small (35mm dia and
> >50mm height).
> >I guess this is designed for Bulk Capacitor
> >in Switching Mode Power Supply.
> >
> My guess is that they are intended for 50/60 Hz service.  Switccher 
> supply caps would need much less C and very low ESR.  
> 
> -  Rich..., 805.386.3734, www.vcnet.com/measures.  
> 
> 
> --
> FAQ on WWW:               http://www.contesting.com/ampsfaq.html
> Submissions:              amps@contesting.com
> Administrative requests:  amps-REQUEST@contesting.com
> Problems:                 owner-amps@contesting.com
> Search:                   http://www.contesting.com/km9p/search.htm

--
FAQ on WWW:               http://www.contesting.com/ampsfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm