Vixen controllers and 12vDC powertank question.

[Franklin]

I know a bit about telescopes but when it comes to electronics I'm in the dark.

I have two Vixen controllers, a DD3 which is 12vDC center positive and a DD1 which is 12vDC center negative. My query is this; providing I use the correct cable and jack plug with each controller, is it ok to power both from the same powertank? I was going to just try it out but didn't want to fry my controllers. Thanks.

[Pixies]

Yep. As long as each power outlet is 12v and it's capable of supplying enough current to both controllers simultaneously.

But it appears the DD1 doesn't like a power supply that exceeds 12v. See:

What is your powertank?

[Pixies]

Oh - and read this to the end:

https://www.cloudynights.com/topic/689242-source-ac-power-supply-vixen-dd-1-dual-drive-system/

[Franklin]

6 minutes ago, Pixies said:

What is your powertank?

Its the SW 17Ah powertank. The DD3 can be powered by an 8 D cell battery pack which lasts quite a while when just tracking with the GP and a bit of centering, but doesn't last at all when hooked up to the SXW with slewing and goto. The DD1 can also be powered by a battery pack but the cable and plug are different, being center negative. I have two cig lighter cables, one is center positive, the other negative. So from what I think the differences between the two (center pos/neg) is taken care of by the different wiring of the plugs. I did read about the DD1 getting by on 9vDC and that long slewing at x32 was to blame for frying controllers on CN. I tend to not have any drive switched on much. I manually move the scope to the area of interest, use the manual slow motions to center in the finder and then switch on the tracking. After that an occasional tweek of the RA and DEC drive to keep things centered in the scope, which is needed as my polar alignment is pretty rough. Slewing over the face of the moon is another time when the x32 slewing is used but I never try to cover vast swathes of sky using this system. Not like a modern goto mount whizzing around the sky from object to object, I'm an old school star hopper and I use the manual slo-mo's most of the time.

[StevieDvd]

When you see mounts, cameras and other astro equipment marked as 12v it can often be run using a car cigarette type connection (up to 13.8v expected), and on reading the specs will state a voltage range like 11v-14v. So unless the specifications actually cover a range over 12v then I'd be careful to keep to a 12v max and not use a supply that exeeds that.

 

[Franklin]

Yes, I don't think its a good idea running an old DD1 from a 12vDC supply. Two reasons: I've been doing some reading and it appears that at 32x speed there is no voltage regulation from the circuit board which can lead to heating up of elements and damage. Apparently at the 1.5x and 2x speeds the voltage is regulated to 5v max, so as long as I don't use the 32x I should be ok. I hooked the DD1 up to a 12vDC battery pack (8 D-cell) and made sure that the polarity was reversed. Sure enough it all worked fine when the controller was set to 1.5x and 2x, it slewed and tracked as it should but as soon as I switched to 32x the motors started chattering and knocking and the back of the controller began to feel warm. I've switched it off and will get hold of a 9vDC battery pack (6x C-cell) with reversed polarity for the old DD1 and forget about trying to run it off a 12vDC powertank. Never had any of these issues with the SW 6vDC drives, I run them off a 5vDC usb powerbank and they've been fine.