Re: Mach2 Slew Speed, Power, and Voltage Question #Mach2GTO


John Upton
 

Seb@stro & Kenneth Tan.

   Regarding the suggestions that I need a lower power mount-side computer, I am where I want to be. I am using a NUC10 system with an i7 six core processor. I spec'ed it that way for several reasons. You are right that DSO imaging is not very taxing on a PC. However, there are other imaging methods than just long exposure DSO and some of them require more compute cycles from the CPU.

   I built my mount-side mini-PC to be power efficient in normal use. The NUC is running with 16 GB RAM and 500 GB fast NVMe storage. If I turn it loose, it draws as much as 90+ Watts. However, I use a custom configuration which allows it to run DSO imaging at an average of about 12 W with an average of 15% CPU utilization. I think that compares well to lower end Mini-PCs which run at similar power levels of 8 to 12 W at 50% or higher CPU utilization.

   I have plenty of battery power available to me. As of now with the Mach2, it is about the highest power consumption component of my imaging rig. My testing so far is showing a total power usage of about 35 Watts with the Mach2, cameras, and NUC (running Cartes du Ciel, PHD2, Sequence Generator Pro, APCC Pro, and PixInsight (also with a low power configuration)). Prior to the Mach2, this was running about 24 W with my SkyWatcher mounts so the Mach2 has increased the power draw substantially. (For the benefits, though, the Mach2 is worth that extra current it uses.)

   My last set of changes for my Mach2 addition is to rewire my DIY battery box for direct output to the Mach2 using only Anderson PowerPole connections. I currently use the standard astronomy / automotive 12 v cigarette sockets for all power plugs on the battery. (That was done because I once saw a person at a regional star party whose imaging was shut down due to a failure of a custom PowerPole power cable for his rig. No one else there had a spare PowerPole cable to loan him. Lots of folks had spare cigarette cables to offer. The lesson learned by me is to make up spares of any custom cables or else keep them all standard.)

   I knew that the cigarette plug was the weak link for higher currents. It has served me well but I had never had a need to draw up to 7+ Amps through one before. It was interesting to see the effects of significant overheating inside the plug from the Mach2 high speed slews.

John

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