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???
08/25/08 17:28
Modified:
  08/25/08 17:29

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#157746 - another interesting waveform
Responding to: ???'s previous message
I just realised that the distorted waveform may not be random afterall. When I zoomed out and set my scope to 5ms, I noted
something interesting.
(see waveform)
(normal)
And this happens only after dc bus voltage is 95V. Actually, for this one, I tried with 1uF instead of 20uF for bootstrap-capacitor.

I am waiting for hi speed optos. (I have been told to use optos for isolation). I will get to you guys after I get more interesting results.
This thing is getting interesting.

List of 12 messages in thread
TopicAuthorDate
3-phase Inverter IGBT phase waveform            01/01/70 00:00      
   you are going to burn the motor            01/01/70 00:00      
      Its a sine PWM            01/01/70 00:00      
      ...or the IGBTs!            01/01/70 00:00      
   i had same problem on a Hitachi 48kw inverter            01/01/70 00:00      
   Gate Drive            01/01/70 00:00      
      The driver cktry and the waveforms            01/01/70 00:00      
         Bootstrap capacitors problems            01/01/70 00:00      
         Some hints            01/01/70 00:00      
            another interesting waveform            01/01/70 00:00      
               No, no....            01/01/70 00:00      
   Voltage rating of bootstrap capacitor            01/01/70 00:00      

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