External DC Power/Synta EQ6

[allenandholmes]

One Australian dealer is warning against using external 12V DC Power Supplies with China/Taiwan made equipment, mainly because of lack of regulation within the equipment itself and the possible voiding of warranty.
I am wondering whether any IIS member has experienced this problem in practice, in particular with the Synta Skywatcher EQ6 (which is now the front runner in my purchasing list) and whether there is any mention of it in the EQ6 warranty.
Regards,
Allen

[lacad01]

I've been using a 5A regulated supply from Jaycar on my older black EQ6, no issues. They might be referring to a non regulated plug pack a.k.a phone charger type of supply (which incidentally wouldn't have enough guts in the first place to power the mount properly)
http://www.jaycar.com.au/productView.asp?ID=GH1379&CATID=27&form=CAT&SUBCATID=381

[bojan]

I am using 12V 3A switch mode power adapter and there are no problems at all.
I think this is more a safety issue....

[bartman]

I'm using same as bojan but only 2.5 A...made in China but has the insulated prongs (on the 250V side)
From Jaycar.....
Bartman

[TrevorW]

No issues with my 5 amp hr purchased out Jaycar just make sure it's a regulated power suuply

[toryglen-boy]

i use the power of suggestion, seems to work for me!

:P

[allenandholmes]

As long as I stay away from unregulated supplies, I will be ok; this seems to be the general consensus. Well that's that problem solved, if it ever was a problem. Thank you for your assistance folks.
Allen

[Dennis]

Hi Allen

I also use regulated mains adapters for my astronomy equipment and I label each one either:

Centre pin +ve, or…
Centre pin –ve

…as most of my gear is designed with the centre pin positive whereas my Vixen mounts have the centre pin as negative and I believe they (vixen) do not have reverse polarity protection which is a barbaric practice by modern design standards IMHO.

Cheers

Dennis

[bojan]

I totally agree..
However, they probably wanted to avoid 0.7V or 1.5V voltage drop (depending on how protection is realised).. Or do they have special connector?

[Dennis]

Hi Bojan

Although I am drifting slightly off topic here, arguably it may be worthwhile if it prevents someone from frying their electronics with the wrong polarity!

The Vixen spec for my DD-1 Controller is a 2mm plug and the rating is 9v-12v DC. This system used Stepper Motors.

For the Vixen Skysensor 2000, it is a 2.1mm plug and the rating is 9v-14v DC. This system uses DC Servo motors.

The Vixen mounts are the older model GP and GPDX. The above plugs are the power plugs (both centre -ve) whereas the connectors to the SS2K motors look like an 8 pin DIN connector.

Cheers

Dennis

[GeoffW1]

Hi,

I just purchased, here in the trading section, an EQ5 mount with motorised axes, the 6V input type, and have been looking around with this issue in mind as well.

I found this bunch with a good range of switchmode and regulated power supplies but have not tried them yet.

http://shop.voltelectronics.com.au/power?cat=23

Cheers

[bojan]

Thanks for the link, Geoff..
The suitable models are :

http://shop.voltelectronics.com.au/6-volt-dc-1-66-amp-10w-switchmode-power-supply.html
(For you: may be OK, current rating is somewhat low)


http://shop.voltelectronics.com.au/power-supply-12v-4a-w-2-1lead.html
(I am using similar model)

http://shop.voltelectronics.com.au/power-supply-module-6-12v-5a-15v-3-8a.html
(This one looks OK for you)

SMPS's are good because they are regulated, usually with tight tolerances, and the noise from them is not a problem for mount (because processor has its own regulator, and the only thing that is powered directly from PS are motors.

[allenandholmes]

The price of those suggestions is attractive as well Bojan, Geof and Dennis - even a pair of them wouldn't break the budget. Thank you - more food for thought.
Allen

[wasyoungonce]

Even Cheaper....here (http://www.andrewscom.com.au/site-section-09.htm)

Andrews Manson SPA-8230, 13.8VDC (23A :eyepop:) with over current and short cct protection...$99.

A bit of over kill but hey!;)

[bojan]

Do not forget, you have to carry this thing in and out..
Too much of an overkill :-)
Good for lab work, though. Or for permanent observatory (with access to mains power)

[wasyoungonce]

Digging up an old thread....

I just converted an unused computer PSU to a 12Volt supply. Heaps of current capacity. Has built in under volts protection & over volts protection & current foldback. Although I suspect this foldback is set to a high current limit. It also has an inbuilt fan that cools according to load & heat.

Anyway...all I did was unsolder all the leads except the 12V & 0V, run this thru a fuse holder & to a Cigarette connector. Run a switch between the green & one of the blacks (power on).

Install a small load resistor...68ohms (to give the 12Volt rail a small load) between the 12V rail & 0V to load down the rail. This increases the saturation in the switchmode transformer so it's regulating better. I used a 10watt resistor & this is around 2W load. I installed this on the case so it sinks heat away.

Runs at 12Volts sweet! I really wanted 13.8V and on some computer PSUs you can adjust the 12V rail but on this one the Over volts kicked in when adjusting it up. I looked at the PWMIC specs but I couldn't get it right so I just left it at 12V.

Anyway a cheap alternate indeed!

Maybe I should do a write up as on mine I needed to re-solder 3.3V & 5V sense wires back onto the main board. There are guides on the internet though!