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Kai Klaas
10/04/05 04:26
Modified:
  10/04/05 04:27

Read: 764 times
Germany


 
#101901 - Current and speed
Responding to: Prahlad J. Purohit's previous message
Prahlad said:
What are the easily availble diodes in SMD package for this application [ freewheeling ].

There are two things to keep in mind, when choosing a free wheel diode, current and speed.

Current: The free wheel diode need not to shunt more current than actually flows through the solenoid, because physics tells, that the current tries to keep on flowing. And if this current is 400mA, then only 400mA will flow through the free wheel diode.

Speed: The mechanismn which provides the inductive kick is very fast. So, if the current is switched-off very fast, then also the inductive kick will rise very fast. In this case also the diode must turn-on very fast, because otherwise the inductive voltage can rise to a dangerous level before the free wheel diode conducts. In such cases it's a good idea to take a transzorb acting as a zener diode. This will even help in speeding up the turn-off time of solenoid. And as only 400mA is flowing you can choose a very tiny one sitting in a SMD-package.

Kai

List of 19 messages in thread
TopicAuthorDate
Freewheeling Diode SOD Package.      Prahlad J. Purohit      09/29/05 06:17      
   General Semiconductor      Erik Malund      09/29/05 07:00      
      Specific part number please.      Prahlad J. Purohit      09/29/05 23:17      
         1n4007      Steve M. Taylor      09/30/05 03:54      
            BAV70 or 1N4007      John D. Maniraj      10/03/05 06:32      
               RE: ' '      Prahlad J. Purohit      10/04/05 08:11      
   Current and speed      Kai Klaas      10/04/05 04:26      
      Re: Current & Speed.      Prahlad J. Purohit      10/04/05 08:09      
         BZD27-C10      John D. Maniraj      10/04/05 22:26      
         KSC2328 is not very fast      Kai Klaas      10/05/05 07:55      
            SMBJ15A/2.....etc      John D. Maniraj      10/05/05 10:15      
               why all the stuff, a Schottky diode does      Erik Malund      10/05/05 10:51      
                  but      Steve M. Taylor      10/05/05 15:53      
                     Funny you should use that word...      Rob Vassar      10/05/05 16:35      
                     so have I, it is quite dramatic.      Erik Malund      10/06/05 06:48      
                        OT: backslashes      Jan Waclawek      10/06/05 07:29      
                  What Schottky diode?      Kai Klaas      10/07/05 04:44      
                     whichever took my fancy that met the req      Erik Malund      10/07/05 07:46      
                        Fuel injectors      Kai Klaas      10/08/05 06:38      

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