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domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 10:09pm 18 Oct 2015

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Hi,

Could not fix the Victron charger/inverter, so I ripped it apart. It contains two Keen Ocean toroidals model TT0-10954-04, 244VAC in, out 14.6VAC 27.5Amps.

Three secondaries with six leads supply about 15.7V with my 250VAC input but there is a 5VAC "leak" from one secondary lead to the center metal part with its two M5 threads, which held two bolts for fixing to the alu chassis.

What am I measuring here, is this part of an induced current I am measuring or is this a leak to earth? In fact when this charger was operating partially it leaked 125VAC to earth. Would like to sell them if they are not "bad" toroids.

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

larny
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Joined: 31/10/2011
Location: Australia
Posts: 346

Posted: 01:17pm 29 Oct 2015

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DMMs have a very high resistance when set to read Voltage. One of mine is 20 M Ohm & the other is 40 M.

I suspect that the voltage you are reading is due to capacitive coupling.

You can confirm this by:-
1. connect the DMM between the points that read 5 Volt.
2. then connect a resistor across the DMM. Any value between 1k & 100 k will suffice.

If the "leakage" is due to capacitive coupling, the voltage will drop to a very low value since the capacitance would not be very large - I would guess about 10 nF.

But if the "leakage" is due to a short circuit or low insulation resistance, then the reduction in the voltage reading will be either nil (if it is a short) or it will not be as great if it is due to low IR.

Let me know how you go.

Larny

domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 01:03pm 11 Nov 2015

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Thanks for help. Am a software person without a black belt in electrickery and will try your suggestion before I sell those two treasure on this forum!

Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up.

Winston Churchill

larny
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Joined: 31/10/2011
Location: Australia
Posts: 346

Posted: 03:15pm 12 Nov 2015

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You're welcome. If you need more help, just ask.

As you're a software persom, perhaps you or some else can help me.

I have a PC running Windows 7. This morning it downloaded 25 updates from Microsoft.

About 3 hours ago, I set it to shut down in order to install the updates.
However, it has been stuck at update 20 for at least 2 hours.

As far as I know, the only option I have is to press & hold the power button until it turns off.
I'm reluctant to do that because I don't want to lose the remaining updates.

Any suggestions will be appreciated.

BobD

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Joined: 07/12/2011
Location: Australia
Posts: 935

Posted: 05:09pm 12 Nov 2015

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Sometimes windows updates will ask for permission to proceed or agreement to a EULA or some other idiotic thing. Look behind the update window and see if another small window exists for the above.

I have never much of a problem with updates. If interrupted they can usually be restarted without too much drama. Just go back into Win Updates again and see what it wants to do.

larny
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Joined: 31/10/2011
Location: Australia
Posts: 346

Posted: 05:40pm 12 Nov 2015

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Thanks for the prompt reply. However, the computer problem resolved itself.

A few minutes after writing the Post (using my wife's computer) I noticed that mine had shut itself down.
So I started it, and after the usual upgrading windows sequence, it came up as normal.
So it must have eventually finished the upgrading.

I have never seen the "ask for permission" that you mentioned.

What did you mean by "Look behind the update window and see if another small window exists for the above"? How do you "look behind the update window"?

I'll keep a copy of your post for future reference.

BobD

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Joined: 07/12/2011
Location: Australia
Posts: 935

Posted: 07:22pm 12 Nov 2015

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Sometimes on the first install or a major update of Skype, Silverlight, or The Malicious Software Removal Tool (and others) will ask for agreement to a Eula before proceeding. I've been caught a couple of times waiting for an update and it was waiting for me.

Minimise the Update window and any others one by one to see if there is a small window asking for agreement to proceed or similar. It seems to pop under rather than in front. Very clever.

larny
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Joined: 31/10/2011
Location: Australia
Posts: 346

Posted: 07:56pm 13 Nov 2015

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Thanks for the response, BobD, however I think we are speaking at cross purposes.

My situation occurred when the PC was doing a Windows update that it downloaded from Microsoft which started when I asked it the Shut Down.

As far as I know, there are no windows behind the Microsoft upgrading window.
It says "Do not power off your computer" or words to that effect.

Anyway, the issue has resolved itself. Thanks again.

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