#11149 NORM 1.75-ha: XO 1.75 B1 may show charging indicator when not charging

[Zarro Boogs per Child]

#11149: XO 1.75 B1 may show charging indicator when not charging
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           Reporter:  greenfeld  |       Owner:  wad          
               Type:  defect     |      Status:  new          
           Priority:  normal     |   Milestone:  1.75-hardware
          Component:  hardware   |     Version:  1.75-B1      
         Resolution:             |    Keywords:               
        Next_action:  diagnose   |    Verified:  0            
Deployment_affected:             |   Blockedby:               
           Blocking:             |  
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Changes (by wad):

 * cc: rsmith (added)


Comment:

 A description of the problem, along with waveforms, is at:

  http://dev.laptop.org/~wad/backward_switcher/

 It can be reproduced with a power supply set to exactly the right voltage
 for a board.

 While this is an annoying artifact of operating at zero input current, we
 do not intend to ever spend time in that state.  The MPPT algorithm should
 immediately decrease LV_SET (the voltage at which current draw is allowed)
 to try to increase the input current if the perceived input power is zero.

 There doesn't appear to be any harm to a laptop experiencing this problem,
 although it is very annoying and should be fixed.

-- 
Ticket URL: <http://dev.laptop.org/ticket/11149#comment:2>
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