You should be aware that under certain conditions, ANY
Pyramid power supply, including the one sold through AP, may NOT reset its
“thermal breaker” after a dropout, for upto a half hour.
So, you may give up and walk away too soon. Then all, is fine the next night,
but the PYRAMID trips again. The Pyramid (old linear technology) supplies are
not very efficient, but are generally well designed. Just heed their warnings
If you still have it, carefully read the
Here is Section #5, which I transcribed from mine.
Substitute “TRIP” ... for their word “WORK”.
Yes, it does “work” as designed to do. The power supply breaker will
trip, eventually, even if there isn’t an immediate short circuit overload.
So, any long duration or repeated mount slews, will eventually have the Pyramid
protect itself, so you can take an imposed coffee break, before going back
to imaging :-)
(A-5) WARNING /
THIS UNIT IS WELL BUILT WITH A WARNING!
SHUT DOWN FUNCTION.
THE WARNING / SHUT DOWN FUNCTION
WILL WORK - UNDER THE FOLLOWING UNUSUAL
THIS UNIT IS USED
OVER 15 MINUTES AT 100% OF RATED LOAD.
IS USED OVER 25 MINUTES AT 80% OF RATED
THE OUTPUT OF THIS UNIT IS SHORT-CIRCUITED/OVER
1) IF THE WARNING/ SHUT DOWN FUNCTION IS CAUSED BY THE ABOVE ITEMS # 1 AND 2 THEN THIS UNIT WILL
RETURN TO NORMAL WHEN THE WARNING/SHUTDOWN FUNCTION CONTINUES TO WORK ABOUT 15-30
2) THIS UNIT IS INTENDED TO
CONTINUOUSLY WORK AT 70% OF RATED LOAD DESCRIPTION OF THE WARNING /
SHUT DOWN FUNCTION:
STEP I. THE OUTPUT SHUT SHUT
GREEN LED OF NORMAL OFF
STEP 3. RED LED OF PROTECTION
Hope this helps explain the situation you had been
having. Check you device power requirements.
When it happened to me, the overload eventually tripped the PYRAMID, and
while I was away from the mount for a short while, the power supply cooled off
and came alive – and the mount resumed its slew, right into the pier, before I
could hit the main power switch. I wish the Pyramid would have stayed powered
off, but it seems to have been designed to reset and resume without warning and
“unattended operation” – NOT always a good thing.
From: CurtisC via groups.io
Sent: Wednesday, April 29, 2020 3:59 AM
Subject: Re: [ap-gto] Mach1 CP3 pier crash!! (Similar to CP4 crash
in another thread)
have an observatory. The Pyramid ordinarily doesn't get very hot. I
tested its output voltage this evening, and it tested at 13.8. So it came
back after appearing dead. Meanwhile, the little Radio Shack p.s. is
connected to the CP3.