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???
02/20/07 12:47
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 		 #133306 - A diode helps.
Responding to: ???'s previous message
According to Lenz, when you interrupt current that circulates thru a inductance (relay coil), voltaje in the coil raises in order to keep the electrons moving. This will produce spikes (and sparks in the interruptor) and all kinds of EMI.
One simple way to minimize this, is conecting a diode (cathode to +12V) in paralell with coil. This will work, but the current the relay interrupts with contacts also will produce spikes. And the results also depend on how the mC PCB layout is designed.
Good luck!
Daniel

List of 51 messages in thread
TopicAuthorDate
How its happen?            01/01/70 00:00      
   correction            01/01/70 00:00      
   my 2 cents            01/01/70 00:00      
   What is exactly RLY fuction?            01/01/70 00:00      
      Effect of relay            01/01/70 00:00      
         Isn't it called EMI?            01/01/70 00:00      
            Sure - radiated and conducted            01/01/70 00:00      
               Ok, thought so :)            01/01/70 00:00      
                  Maybe it's a test?            01/01/70 00:00      
                     Not very kind to operator :)            01/01/70 00:00      
         A diode helps.            01/01/70 00:00      
            But immunity is best!            01/01/70 00:00      
         Arcing machine            01/01/70 00:00      
            RF oscillations            01/01/70 00:00      
               School experiment            01/01/70 00:00      
   Ok, we posted in the same minute :)            01/01/70 00:00      
      This time it was Andy and AGAIN same time :)            01/01/70 00:00      
      I'll build in some random delay next time :-)            01/01/70 00:00      
   the solution will be here            01/01/70 00:00      
   I'm puzzled            01/01/70 00:00      
      It damps out the relay voltage spikes?            01/01/70 00:00      
         not much, if any - 33pF?            01/01/70 00:00      
            Should be a printing error.            01/01/70 00:00      
   let's focus            01/01/70 00:00      
      Of course it is possible.            01/01/70 00:00      
      why focus            01/01/70 00:00      
         because......            01/01/70 00:00      
            Part more susceptable to EMI?            01/01/70 00:00      
            'experiment' all you want            01/01/70 00:00      
            prevent problems            01/01/70 00:00      
      where did we not focus?            01/01/70 00:00      
         conclusion            01/01/70 00:00      
            You are a funny guy...            01/01/70 00:00      
               chips is different            01/01/70 00:00      
                  already answered            01/01/70 00:00      
                  That's the definition of "Unreliable"!!            01/01/70 00:00      
                  pure unadulterated male cow manure            01/01/70 00:00      
                     The Relay            01/01/70 00:00      
                        The purpose of a Watchdog            01/01/70 00:00      
                           Woof            01/01/70 00:00      
                              Grrr            01/01/70 00:00      
                                 Watchdog Hit Report            01/01/70 00:00      
                  Some hints...            01/01/70 00:00      
                     The decoupling Cap            01/01/70 00:00      
                        With shortest leads to Vcc and GND pins            01/01/70 00:00      
                     What software,Kai?            01/01/70 00:00      
                        Target            01/01/70 00:00      
                           yes            01/01/70 00:00      
                     Thankyou Kai            01/01/70 00:00      
   isn't it obvious?            01/01/70 00:00      
      No you missed that it is the coil...            01/01/70 00:00      

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