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???
09/20/10 20:48
Modified:
  09/20/10 21:01
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 		 #178609 - Voltage - or power? [ed]
Responding to: ???'s previous message
Kiran V. Sutar said:
till the Temperature reaches 100 Degrees, We are NOT supposed to give full voltage (sic?) to the heater. We are supposed to give only 30% of the voltage (sic?) to the heater, till it reaches a temperature of 100 Deg.C.

Do you really mean voltage there - or should that be power?

Later you can give full power.

As here, power would seem to make more sense.

Note that there's nothing in Michael's scheme that would prevent you from achieving a 30% power limit...

Edit:
I take that back - see: http://www.8052.com/forumchat/read/178610



However, does the fact that this limit is imposed suggest that the heaters are susceptibe to damage by over-current (or over-voltage) when cold?

Are you certain that your system strictly meets this requirement?

List of 41 messages in thread
TopicAuthorDate
What is the reason for Heater blowing.            01/01/70 00:00      
   Hof often/how we?            01/01/70 00:00      
      Some more information...            01/01/70 00:00      
   continuous rating            01/01/70 00:00      
      This could be the reason...            01/01/70 00:00      
   Way too much current...            01/01/70 00:00      
      Some more information required...            01/01/70 00:00      
   do you have hysteresis in your control?            01/01/70 00:00      
      No there is no hysteresis.            01/01/70 00:00      
         Four pulses?            01/01/70 00:00      
            The Heaters are failing, electronics is OK.            01/01/70 00:00      
               Why Pulses?            01/01/70 00:00      
                  I will do just that...            01/01/70 00:00      
                     Processor must know about zero-crossings            01/01/70 00:00      
               ??            01/01/70 00:00      
                  soft start            01/01/70 00:00      
                     Soft Start            01/01/70 00:00      
                        an easy and interesting check            01/01/70 00:00      
                           Soft start, again...            01/01/70 00:00      
                  Yes these heaters need Soft start            01/01/70 00:00      
                     Again: Power? Voltage? Current?            01/01/70 00:00      
                        Avoid driving gate all the way to next zero crossing            01/01/70 00:00      
                           Crest factor/power factor correction            01/01/70 00:00      
                     Phase angle control...            01/01/70 00:00      
                        I agree with you.            01/01/70 00:00      
                           Good luck!            01/01/70 00:00      
                           are all heating coils the same ?            01/01/70 00:00      
                           There You Go            01/01/70 00:00      
         re the possible need for hysteresis            01/01/70 00:00      
         Power? Voltage? Current?            01/01/70 00:00      
   Alternate Heating Control Algorithm            01/01/70 00:00      
      Some more clarification...            01/01/70 00:00      
         Voltage - or power? [ed]            01/01/70 00:00      
   The other controllers            01/01/70 00:00      
   Thanks All members.            01/01/70 00:00      
   just suggest..            01/01/70 00:00      
      Reply to JecksonS Ben            01/01/70 00:00      
         Good point!            01/01/70 00:00      
            supposed to            01/01/70 00:00      
         opto isolated triac            01/01/70 00:00      
   My solution            01/01/70 00:00      

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