Thanks Ed
I'm happy to share my experiences in this, because it is so easy to make silly mistakes, and since I won't be doing this again, I hope someone will benefit from it.
Part 2 of the electrical set up. !
It is amazing how many accessories are powered by 12v. For this reason I have 2 x 12v power supplies which are plugged into the observatory mains sockets. Specificaly I use these.
https://www.firstlightoptics.com/batter ... upply.html They are useful because it shows you how much power is being drawn at any particular time.
One of them is used exclusivley for the telescope mount. That uses a lot of amps when slewing the telescope, and it is easy to underpower it if other things are using the same power supply at the same time. Underpower the mount and it will lose alignment.
I use 12v LED light strips. Dozens of white ones to illuminated the inside of the observatory, and a group of 3 red ones for the equipment bay. This helps preserve the night sight of the eye when observing. They are individually switched. I have dew heaters on the main telescope and guidescope/ wide angle scope, they are powered from the 12v supply. The 12v supply also powers the 'All Sky camera', and a small monitor in the equipment bay. There is also a Canon camera power supply from the 12v. It is very frustrating to have your camera battery go low in the middle of a session.
Increasingly I find accessories are powered by 5v USB connectors. A mains supplied USB hub is probably best for this, although a group of 5v USB sockets which are powered from 12v batteries are useful. They are the same kind that you find in your car. I have both of these, but the car ones are limited to 1 or 2 amps. There are higher rated 12v to 5v convertors, but they are a little expensive and I find they are hard to come by. This is 3A supply.
https://www.firstlightoptics.com/zwo-ac ... 2v_5v.html