Email: Password: Remember Me | Create Account (Free)


 

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Erik Malund
11/28/11 06:55
Read: 155 times
Mt Airy, Nc
USA


 		 #184928 - still missing the point
Responding to: Richard Erlacher's previous message
In linear supply design, the filter cap design is classically based on "tolerable" ripple under full load. The old (Originated with NSC) formula for computing filter cap size (before the regulator) was
8000 uF / ampere at full load / volt of tolerable ripple, or something on that order

with PFC (getting more and more mandatory) the "primary step down" will be a switcher and your linear regulator will not need concern itself with 120Hz ripple, but with ripple in the kHz/MHz range.

Erik

List of 26 messages in thread
TopicAuthorDate
a myth debunked ?      Erik Malund      11/25/11 10:21      
   Same old?      Andy Neil      11/26/11 05:43      
   Hhm...      Kai Klaas      11/26/11 07:45      
      no, I did not      Erik Malund      11/26/11 07:48      
         Babble of marketing people...      Kai Klaas      11/26/11 08:06      
            read it all      Erik Malund      11/26/11 08:16      
               There's no need for HF-ripple rejection...        Kai Klaas      11/26/11 09:05      
               ... what's more important ...      Richard Erlacher      11/26/11 09:11      
                  whatever      Erik Malund      11/26/11 09:37      
                     But the article claims it...      Kai Klaas      11/26/11 09:57      
                        even the article states      Erik Malund      11/26/11 10:48      
                           Switchers ARE beautiful...      Kai Klaas      11/26/11 13:20      
                        do linear regulators ever "produce" ripple?      Richard Erlacher      11/27/11 00:39      
                           getting more and more irrevelant      Erik Malund      11/27/11 07:32      
                              Perhaps, but where else would ripple originate?      Richard Erlacher      11/27/11 10:09      
                                 still missing the point      Erik Malund      11/28/11 06:55      
                                    Why do you see this as "becoming more mandatory"?      Richard Erlacher      11/28/11 08:45      
                                       you can't do PFC without      Erik Malund      11/28/11 09:04      
                                          Vice versa...      Kai Klaas      11/28/11 11:57      
                                             Not so fast      Rob Klein      11/28/11 14:26      
                                          fortunately, PSU's are not on my deliverables list      Richard Erlacher      11/29/11 15:29      
                                       I'm with Eric      Oliver Sedlacek      11/29/11 08:14      
                                          Disadvantage of switched-mode supplies...      Kai Klaas      11/29/11 12:04      
                                             Huge crest factor      Per Westermark      11/30/11 03:58      
                                                Numbers...      Kai Klaas      11/30/11 08:30      
                           It depends on load      Mahmood Elnasser      11/27/11 08:28      

Back to Subject List