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???
08/01/11 10:07
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#183126 - Surge protectors, zener + crowbar
Responding to: ???'s previous message
I've designed certified overvoltage protectors in the past that basically use a fuse and an SCR to crowbar and blow the fuse. You also use a zener to clamp the spike during the time it takes the SCR to fire.

Question 1. What fuse rating should I pick for an HDD 12V rail? The spindle motor startup current can be substantial, so I would guess about 5A.

Question 2. What voltage should trip the SCR. The PC PSU 12V supply probably has a 5% tolerance, so it would have to be more than 12.6V. Will an HDD tolerate 14V on the 12V supply?

List of 15 messages in thread
TopicAuthorDate
HDD surge protector, what would it take?            01/01/70 00:00      
   My thoughts...            01/01/70 00:00      
      Backups            01/01/70 00:00      
         Other Discussion            01/01/70 00:00      
            A good PSU is a good investment - backup policy even better            01/01/70 00:00      
               How good is a good PSU?            01/01/70 00:00      
            Similar experience            01/01/70 00:00      
               maybe you need some power zeners            01/01/70 00:00      
                  Surge protectors, zener + crowbar            01/01/70 00:00      
                     a zener is too slow            01/01/70 00:00      
                        maybe not            01/01/70 00:00      
                        How slow is slow?            01/01/70 00:00      
                     HDD +12V            01/01/70 00:00      
                        PSU allowed to do +/- 10% on 12V rail at max load            01/01/70 00:00      
                           That's useful            01/01/70 00:00      

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