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Date: Sat, 10 Sep 2005 14:29:13 -0500
From: Jim Sower <canarder@frontiernet.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Overvoltage control (help Ed A)
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No.  It is designed to output 14.4 - 14.7V and that's what it does.  I 
think adjustments are for units that wander a lot and won't hold a setting.
Why would I want to adjust what's right (Harvey's Second Law) ... Jim S.

Mark R Steitle wrote:

>Is your internally regulated alternator adjustable?  
>
>-----Original Message-----
>From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
>Behalf Of Jim Sower
>Sent: Friday, September 09, 2005 2:32 PM
>To: Rotary motors in aircraft
>Subject: [FlyRotary] Re: Overvoltage control (help Ed A)
>
>If my crowbar overvoltage opens the B+ circuit, there's NO current 
>flowing out of the alternator.  Absent current, there can be no heat 
>generated.  The field can go to max output, there will be high voltage 
>at the B+ terminal, but no heat generated.  Sounds to me like a bogus 
>concern.  I think the key issue is "... Nuckolls expressed dislike ..." 
>and no further support is "needed".
>
>Still looking for a "real" reason ... Jim S.
>
>Mark R Steitle wrote:
>
>  
>
>>Jim,
>>I first explored this issue after Bob Knuckols expressed a dislike of
>>internally regulated alternators...because they can fail in such a way
>>that you cannot shut them down.  Yes, you can interrupt the "B" lead,
>>but this will not shut down the alternator.  I imagine it could get hot
>>enough to self-destruct and possibly catch fire.  
>>
>>The modification I use removes the internal regulator assembly and puts
>>a direct (external) feed line to one of the brushes.  The other brush
>>    
>>
>is
>  
>
>>tied to ground.  Nothing else is connected to the field.  With this
>>arrangement, can you explain how removing power from one of the brushes
>>will allow the alternator to continue producing power?  I've tested my
>>modified alternators with the engine running and it does in fact stop
>>producing power when I cut the power to this lead.
>>
>>Another benefit to an external regulator is that you can precisely
>>adjust the voltage, provided you use an adjustable regulator.  
>>
>>Mark S.  
>>
>>-----Original Message-----
>>From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
>>Behalf Of Jim Sower
>>Sent: Thursday, September 08, 2005 5:31 PM
>>To: Rotary motors in aircraft
>>Subject: [FlyRotary] Re: Overvoltage control (help Ed A)
>>
>>I've always been puzzled why folks would go to all the trouble of 
>>disabling a perfectly good internal regulator so as to install an 
>>external unit.  If the Field circuit gets somehow internally shorted to
>>    
>>
>
>  
>
>>the output circuit, the alternator is going to run away and create an 
>>over voltage condition.  In that event, there's no way that turning off
>>    
>>
>
>  
>
>>current to the Field is going to help you.  Other than a short 
>>described, I don't know how an over voltage can occur.  So my question 
>>is:  is an internally regulated system all that much more apt to have
>>    
>>
>an
>  
>
>>over voltage type failure, and if so why?  I've had lots of trouble
>>    
>>
>with
>  
>
>>externally regulated alternators, very little with internal regulators.
>>
>>My crowbar over voltage system is bullet proof.  It's the only scheme 
>>that prevents damage caused by an internal short in the alternator.
>>What, exactly, is the big attraction of external regulators? ... Jim S.
>> 
>>
>> 
>>
>>    
>>
>
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>  
>