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???
08/25/05 11:54
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#100062 - No buts
Responding to: ???'s previous message

The problems with relays are well known and understood. Choosing a suitable relay and protection circuit is much easier than using a triac (in my opinion anyway). If we're talking about a significant amount of current, you'll need a heatsink on the triac which normally negates any size advantage. My background is in power control - more specifically lighting control. So, I've used a few triacs in my time and a few relays. I'm not saying triacs are inherently bad, they are fairly reliable but they need more care and feeding compared to a humble relay. Relays also have a higher demonstrable reliability.

Put it this way, get a 10A relay - garden variety. Feed it 230VAC through a standard C curve din rail 10A circuit breaker into a short circuit. See how many times you can activate the relay before it fails. Now try the same with a 16A triac (40A if you like) - it will most likely fail the first time and generally will not survive past 3 times. Also, with the triac you normally require an optocoupler - these too have issues of wearout. Also look at the cost implications - a 10A name brand relay costs me about AUD$5 in small quantities with a led indicator. An equivalent SSR (solid state relay) is at least AUD$20.

Ask yourself "what is safer"


List of 23 messages in thread
TopicAuthorDate
What is a safer?            01/01/70 00:00      
   Think about it            01/01/70 00:00      
   hmmmm            01/01/70 00:00      
      Why not just use a relay?            01/01/70 00:00      
         Agree but....            01/01/70 00:00      
            Hmm...            01/01/70 00:00      
         Relay            01/01/70 00:00      
      philips            01/01/70 00:00      
   No buts            01/01/70 00:00      
      Is it rocket science then?            01/01/70 00:00      
         What's non-ideal?            01/01/70 00:00      
            even with a triac you still need a relay            01/01/70 00:00      
            Relays            01/01/70 00:00      
               the life of a relay            01/01/70 00:00      
                  Try this            01/01/70 00:00      
                  Contactors            01/01/70 00:00      
                     motor specs            01/01/70 00:00      
                        Mechanical things            01/01/70 00:00      
                     Yebbut            01/01/70 00:00      
               Use the math Luke            01/01/70 00:00      
   Dumbass customers            01/01/70 00:00      
      War Stories - New Thread?            01/01/70 00:00      
         Since Craig is adept at moving posts, I'            01/01/70 00:00      

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