SX problem.............give me strength!!!!!!

[Fay]

I do charge them after every session.

I am thinking, that last time I used the SX, i ran mains power up the garden, I cannot really remember, but this is possibly so.

I will be able to light up Bromley the amount of batteries I will have!!

[RobertM]

I will be able to light up Bromley the amount of batteries I will have!!

Well at least we'll know where all the light pollution is coming from 

[Fay]

This is what Terry Platt said:



It's the different ground connections that cause the problems. You are forcing the computer ground to be the same as the camera ground when you run them from the same battery. This is not recommended and is probably causing problems with the signalling from the computer.

[mickw]

You just need a link between both batteries, probably just the negative.
Doesn't have to be a thick cable either

[Fay]

Oh, so two batteries would then serve, mount, laptop, SX?

[mickw]

I would think so - Just re-read terry platts message, it looks like he's suggesting camera on it's own battery and run the mount and laptop off a seperate one. 

Anybody else having to use 2 batteries ?

[Fay]

Yes but mount will not run off battery with anything else

[Mac]

My paper work with the HX9 say DONT run the laptop and camera off of the same battery, use two different ones.

I just use the inverter for one of them, that way the voltages are not referenced to each other,
eliminating the grounding problems.

I know an inverter is inefficient, but it will solve the problem.

If you use two batterys, dont connect them together, leave them separate.

~Mac.

[RobertM]

I remember having big problems with the SXV-H9 when I used a 12v PSU to power the laptop from the same battery for just that reason.  Mac's solution of an inverter will isolate the laptop and solve that problem.  In the field I always power the laptop that way with a seperate battery and have never had a problem.

Robert

[Fay]

That was going to be my next question, how do Mac & Robert power their Sx camera's. I thought you plugged everything into a multi cig connector.

Also, I do have an inverter, but they take a lot of power themselves, don't they?

[Fay]

Last night, this reply was put om UKAI in answer to my question:

From the Winchester Electronics SX website, http://www.starlightccd.com/ under the questions and answers, it states the following:

5. How do I run my camera off 12VDC? Go To TopQ&A Go To TopTop
    There is an orange 2-pin DC power connector on the side of the power block. It is polarity protected by an internal diode and the lower pin is the positive terminal.

        NOTE:To be absolutely safe, do not run your camera and computer from the same battery, or serious damage could result! All the cameras should be safe when running from the battery used for the telescope drive. You should also be able to connect the laptop to the same supply, if it is via an inverter. The only reason for the caution about common battery supplies is because you may damage the laptop parallel port if the camera tries to take its cooling current via the computer ground. This is unlikely to happen, but not impossible.

            The main reason for this is to avoid the possibility of a 'ground loop' through the computer printer port. For example, if the camera and computer are running off the same DC supply, the negative of the camera supply will also be applied to the computer parallel port, via our cable. If the camera or computer negative lead becomes disconnected from your battery, the camera or computer will continue to run via the parallel port ground connection and it can be subjected to several amps DC.

            Another possibility is that the computer 0V supply is not directly connected to the chassis of the machine, and this can also set up currents between the camera and computer.

            If you are sure that neither ground lead will become disconnected and that the grounds are 'common', there should not be any problem, but be cautious! Otherwise, using the AC input via an inverter is quite safe.

When I think my fuse kept blowing!!!!!

[mickw]

So mount and camera is OK on one battery, but have laptop on a different one 

I think all your power leads could do with checking as well - something started all this off 

[Fay]

Well Mick, my mount will not operate with anything else.


I used to use an inverter, until Ian told me it was taking a lot of the battery power for itself. That may be when I last used the SX in the field. Which would explain why it was working ok then.

Bit scary I  could have done damage to the laptop. Hope it has not got anything to do with all this DMK malarky!!!!!!!!
 Do you think, Mac?

Also, is the 17 ah yellow jumpstart not powerful enough for the SX? It would not work with that on it's own.

It is getting like an Agatha Christie mystery!

[mickw]

According to the SX M7 overview, the camera uses less than 1 Amp, so your yellow battery (17AH) should keep it ticking over for 17 hours 

Probably a dumb question, but is the yellow battery Fully charged ?

[Fay]

Yes, I only use it for dew heaters. All my batteries are charged after every session. I should think about a leisure battery, but they are too heavy for me.