Re: AP900 CP2 Issue


Joe Zeglinski
 

Hi Chris,
 
    Well we can rule out “motor stall” and ignore THAT meaning of the Amber LED – with the 4 motors stalling all at once  and working perfectly when the CP4 is replaced with the old CP3.
 
    Low voltage “as supplied” – can be ruled out – all 4 motors run like hell, out of control, with 14 volts provided by either one of the 2 different supplies, even with one test mount carrying only about 4 lbs (a bare D-Plate).
 
    Seems to narrow it down to a 12 vdc to 5 vdc  (logic level) conversion which is weak or lost,  internally.
No worries - Howard will soon figure it out, though it was still a mystery when we ran some tests (via remote). I’ll leave it to AP to do the rest of the sleuthing, since we’re just throwing darts in the dark.
Really odd situation, however – I just have a knack of falling into them.
 
    I’m confident some weak CP4  (internal) component failed after nearly 24 hours of actual use, over the months since CP4 delivery. Good to always have a simpler, spare CP3 in one’s kit.
 
Joe
 

From: 'Christopher Erickson' christopher.k.erickson@... [ap-gto]
Sent: Sunday, August 6, 2017 5:32 PM
To: ap-gto@...
Subject: RE: [ap-gto] AP900 CP2 Issue
 


I have only ever seen low voltage uncontrolled slewing with the CP2.  I have never seen it with the CP3 or CP4.
 
Both the CP3 and CP4 have low voltage detection and slew lockout features.  That's one of the things that will trigger an amber indicator LED on those controllers.  As will detecting a motor stall.
 
 
-Christopher Erickson
Observatory engineer
Summit Kinetics
Waikoloa, HI 96738
www.summitkinetics.com
 

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