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???
10/01/10 19:26
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#178843 - no
Responding to: ???'s previous message
Assume PC817 "C " - with minimum tranfer ratio==200% .
50mA/2 = 25 mA in best case.
But - You should specify "C" grade
- You should ensure these 25 mA
For me this is unacceptable solution for instrumental devise.

If You choice 5 mA LED current , minimal quaranteed output of any PC817 is 2.5 mA .
And this current is enough to switch on any P-N-P transistor , which will drive relay.

If optoisolator is needed at whole....
regards




List of 13 messages in thread
TopicAuthorDate
PC817 for isolation + driving relay?            01/01/70 00:00      
   Why isolate relay coil?            01/01/70 00:00      
      Re:            01/01/70 00:00      
         Optos don't actually "isolate" from a EMC point-of-view...            01/01/70 00:00      
            .........            01/01/70 00:00      
               Star point grounding and filtering...            01/01/70 00:00      
   PC817?            01/01/70 00:00      
      Is LED current of 5mA is sufficient?            01/01/70 00:00      
         no            01/01/70 00:00      
            A darlington?            01/01/70 00:00      
            SSR?            01/01/70 00:00      
               RE: "book by Bosshcart "            01/01/70 00:00      
                  RE: "book by Bosshcart " - Link            01/01/70 00:00      

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