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???
11/30/11 10:58
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 		 #184952 - Huge crest factor
Responding to: ???'s previous message
The problem with a transformer followed by rectifier and capacitor is the huge crest factor. It will only draw current from mains during the tiny time at the peaks, when the capacitor needs to be topped up.

So the legislation is constantly reducing the maximum power you may have with this type of design.

A 5W PSU with a crest factor of 10 is loading the mains as much as a 50W PSU.

List of 26 messages in thread
TopicAuthorDate
a myth debunked ?            01/01/70 00:00      
   Same old?            01/01/70 00:00      
   Hhm...            01/01/70 00:00      
      no, I did not            01/01/70 00:00      
         Babble of marketing people...            01/01/70 00:00      
            read it all            01/01/70 00:00      
               There's no need for HF-ripple rejection...            01/01/70 00:00      
               ... what's more important ...            01/01/70 00:00      
                  whatever            01/01/70 00:00      
                     But the article claims it...            01/01/70 00:00      
                        even the article states            01/01/70 00:00      
                           Switchers ARE beautiful...            01/01/70 00:00      
                        do linear regulators ever "produce" ripple?            01/01/70 00:00      
                           getting more and more irrevelant            01/01/70 00:00      
                              Perhaps, but where else would ripple originate?            01/01/70 00:00      
                                 still missing the point            01/01/70 00:00      
                                    Why do you see this as "becoming more mandatory"?            01/01/70 00:00      
                                       you can't do PFC without            01/01/70 00:00      
                                          Vice versa...            01/01/70 00:00      
                                             Not so fast            01/01/70 00:00      
                                          fortunately, PSU's are not on my deliverables list            01/01/70 00:00      
                                       I'm with Eric            01/01/70 00:00      
                                          Disadvantage of switched-mode supplies...            01/01/70 00:00      
                                             Huge crest factor            01/01/70 00:00      
                                                Numbers...            01/01/70 00:00      
                           It depends on load            01/01/70 00:00      

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