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QHY10 Shut down Computer

QHY10 Shut down Computer
« on: November 14, 2014, 01:59:39 PM »
Hi,
 I just got QHY10 and star testing it and notice problem.

 I encounter problem with QHY10 that when I connect DC power to 201 power supply, it cause computer to shut down. I need to disconnect DC power supply - my computer run with 19V AC adapter. - to restart computer. After reboot, device manager indicated USB hub has problem and I need to disconnect and connect USB cable to recover. This USB hub was working fine for QHY5L-II and Nikon D800 before.

Here is the procedure I did.

Connection
QHY10 is connected through USB hub on my telescope mount. There is no other device connected to this hub.

1.Connect USB cable to QHY10
*Confirm LED is ON
2.Connect power cable to QHY10 and 201
3.Connect DC power to 201
*This cause computer to shut down.

I performed test to avoid this issue.

Solution 1.
Both computer and power supply was connected to same power strip. I changed QHY10 power source to another plug and it fixed the problem

Solution 2.
QHY10 and computer is connected to same power source. But changed connection procedure.

1.Connect power cable to QHY10 and 201 power supply
2.Connect DC power to 201 power supply
3.Connect USB cable

This isn't the way manual describe but fixed the problem.

From these experience, I suspect connecting DC power to 201 poser supply cause electrical spike or something which cause computer to shut down and cause problem to USB hub. Only think I don't understand is that taking AC power from another source fix the problem.

My power strip can take up to 1500W and I don't think it exceed capacity - Computer, Telescope Mount Power, QHY10, focus motor controller is connected and it is under 600W.

Here is my question:
Has anyone see this problem before?
Is this indicate AC adapter or 201 power supply problem?
Is it OK to connect USB at last instead of first?

Taking AC power from different source isn't good option when I image remotely. I really appreciate any help or suggestion to fix my issue.

Hiro.



Gama

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Re: QHY10 Shut down Computer
« Reply #1 on: November 15, 2014, 11:49:36 PM »
Nothing different here.
Any device that has its own power supply will have a differential voltage difference if the grounds are either not there, or a fair distance away from each other.
If one or both power supplies doesn't have an earth, you will have this issue.
You MUST regardless of ANY device, connect the power supplies together via the equipment.
By this I mean, you need to connect ALL your devices via USB and connect the power supplies to the mains AC supply BEFORE applying/powering on the power supplies.
This makes a pseudo earth (Connects the power supplies to a common earth between them selves) and then everything is fine.
The same for powering down. Turn off one or the other power supplies BEFORE removing the USB.
Because the USB carries the "Earth" or common connection, and so also carries a very high voltage (Sometimes the full AC voltage, but small current).
You can sometimes notice this when you place your nose tip to the Mount or something else metal and you feel a tingle. This is the floating voltage from a uncommon earth/ground.
Remember, connect ALL USB devices first, then power on the supply.

Theo.

Re: QHY10 Shut down Computer
« Reply #2 on: November 16, 2014, 12:51:38 AM »
Theo,

I had problem when everything was connected to same ground. Computer power supply has ground also as QHY10 power supply.

I had this problem when QHY10 and Computer connected same ground. When I connected to different power source for QHY10, problem didn't happen.

So this isn't ground issue. I really appreciate if you read my post more carefully.

Thanks,

Hiro.
« Last Edit: November 16, 2014, 01:42:14 AM by hhakozaki »

Gama

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Re: QHY10 Shut down Computer
« Reply #3 on: November 17, 2014, 01:45:04 AM »
You just answered you own question.
The fact that you changed the power supply fixed the problem says that your power supply was the main cause.
The camera does not do anything else apart from internal voltages, and these do not propagate to the camera body.
If they did, then it would short out the cameras power supply.

You have a ground loop, and I suggest you read a little about ground loops. Even when connected to the same House earth you may still have a issue.

Best way to check for loops is to use a multimeter if you have one to check yourself without earths tied together, measure across both earths (AC of course).

Theo.

Re: QHY10 Shut down Computer
« Reply #4 on: November 17, 2014, 03:34:52 AM »
Hi,
 I did't change power supply. I just connect to different AC power source when I tested at home. As for ground, another power source was connected to same breaker. So should be sharing same ground.

Hiro.

Gama

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Re: QHY10 Shut down Computer
« Reply #5 on: November 19, 2014, 01:46:36 AM »
Without connecting the USB to the camera, measure the voltage from one earth (Shell of USB plug) to the earth of your laptop.

Secondly, if you remove your Laptop power supply from the mains power (Wall socket) so its on battery, and the camera connects fine when you plug it in the laptops USB, and your laptop is still ON, then its a EARTH Loop issue.
Just because you have the AC side in the AC sockets earth, doesn't mean the DC side is earthed. The supplies are Switchmode, and they don't always have a common earth. This is most likely what you have.
I cant keep going on about this. I hope it all works for you. Good luck.
You need to at least measure the two supplies separately before connecting them together.

Theo.
« Last Edit: November 19, 2014, 01:49:17 AM by Gama »

Re: QHY10 Shut down Computer
« Reply #6 on: November 19, 2014, 02:10:26 AM »
Hi Theo,
 As for my computer, it is small desktop computer with AC adapter - Intel NUC Computer. So not option for battery.

 As for quick check, I checked DC output of both AC adapter - QHY10 and computer - and voltage difference is 0V. I checked resistance and it is connected.

 So QHY10 and Computer has same ground level. Is this good enough for proof?

Hiro.

Re: QHY10 Shut down Computer
« Reply #7 on: November 19, 2014, 10:50:10 AM »
Hi Theo,
 I'm really Sorry for my response to your reply. I found your suggestion was right. Here is what I found.

 As I stated, DC power ground was fine. Then I realized I connected camera through USB hub on my mount - iOptron CEM60.

 I tested without USB hub and it worked fine. I checked ground of USB HUB and it only connect ground line of USB. USB casing isn't connected to the ground of USB. I connected casing ground and problem was solved.

 I'm sorry again and thank you for your help.

 Now I need to contact iOptron about this issue.

Hiro.

Gama

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Re: QHY10 Shut down Computer
« Reply #8 on: November 20, 2014, 11:35:28 PM »
Hi Hiro,

Glad to see you found the fault.  8)
 Do not worry too much, as we all go through these problems.
However, it is ALWAYS a good idea to listen and try, even if it is a stupid request.
It is because we all went through the same problem, except we found the cause in the end. So experience is always a good thing.
I had your problem many times. Which is why I asked you to do these tests.
You now will also be a expert here too, for this issue.
So goes to all out there. No one is perfect. Its worth a try and at worst, you wasted a little time.

Theo.