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Voltage supply monitor?

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Voltage supply monitor?

Postby adrian_k » Fri Jul 24, 2020 10:27 am

Hi,

This is not really a studio design question so mods please move if it's in the wrong place. (Although I guess it could be relevant to studio design).

I want to monitor my power supply. Ideally I'd want a log of under or over voltages and interruptions with time/date. I've had a quick search and from what I can see there are various 'energy' monitors out there but I'm not sure they will log voltage performance, they are more about calculating energy costs.

I could just buy a UPS which will give me monitoring but I want to do the monitoring to see if I need one!

The reason I'm doing this is that my internet connection drops at roughly the same time every day. I've been ignoring it as it is a slight annoyance but can live with it. However, this morning my NAS restarted at the same time and it thought it had had a power outage. The router did not power down (wifi was still active) but it's suspicious that the NAS went down at the same time as the connection dropped.

Would be grateful for any input!
cheers
A
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Re: Voltage supply monitor?

Postby Hugh Robjohns » Fri Jul 24, 2020 11:08 am

adrian_k wrote:I could just buy a UPS which will give me monitoring but I want to do the monitoring to see if I need one!

You're in the UK, so you really won't need to worry about sustained under or over-voltages too much. And you'll know about significant interruptions because all the lights and other equipment will go off... :lol:

The reason I'm doing this is that my internet connection drops at roughly the same time every day.

That's odd... There may be some data-logging within the router that could identify the reason for the broadband outage. Worth checking. It may be an issue with the equipment at the local telephone exchange and/or some work practice there. Worth a conversation with OpenReach.

But if you suspect the mains power, does anything else turn off at the same time? Do the lights momentarily dim in brightness?

...this morning my NAS restarted at the same time and it thought it had had a power outage. The router did not power down (wifi was still active) but it's suspicious that the NAS went down at the same time as the connection dropped.

It is suspicious, I agree. Most devices have sufficient power reserves in their power supplies to ride over a brief (milliseconds) outage.

If you have (or can buy) a very cheap moving coil microphone (the cheaper and nastier the better!) you could bodge up something that should record and reveal any significant mains dips. Find a table lamp or something that you can power up and leave on for the duration, ideally in a quiet, undisturbed room. Then wrap the mains cable around the moving coil mic so that the mic picks up the mains hum well -- some experimentation might be needed to optimise the pickup. Record the output of the mic in your computer for the duration, noting the start time for a logging reference. You should then have a basic 50Hz waveform with lots of harmonics (100, 150, etc), the amplitude of which should remain constant. If there are any big spikes or dropouts, or periods of low voltage you should see them in that waveform recording.

Personally, though, if you have a load of computer gear and are moving important files around -- and a NAS box suggests you might -- I'd get a decent UPS anyway. Ideally an online one, although they are expensive.

I use an APC online UPS one that powers my broadband router, wifi repeater, ethernet switches, four NAS boxes, my main computer and its monitor screens, a desk lamp, and a few other bits and pieces -- primarily because the village is fed by overhead lines and we get several outages and brownouts through the year, especially when the wind gets up!
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Re: Voltage supply monitor?

Postby MOF » Fri Jul 24, 2020 12:05 pm

The reason I'm doing this is that my internet connection drops at roughly the same time every day.

That's odd... There may be some data-logging within the router that could identify the reason for the broadband outage.

I have Virgin Media and when I’m watching TV late at night operation freezes i.e. if I rewind live TV at midnight or 1am I can’t stop it, it just keeps rewinding. I think this is when new TV Guide information is being added.
Also sometimes the TV box just powers down and reboots, yet again only in the early hours, although last night it happened at 10pm.
I don’t do internet stuff at the same time so I don’t know if it’s affected too.
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Re: Voltage supply monitor?

Postby Trevor Johnson » Fri Jul 24, 2020 12:46 pm

The company that manages your electricity supply, (not your energy supplier), may be able to help. Ours is Northern Powergrid, who are very helpful. They have the means to temporarily install logging equipment to monitor supply or suggest the reason for the issues you experience.
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Re: Voltage supply monitor?

Postby wireman » Fri Jul 24, 2020 6:47 pm

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Re: Voltage supply monitor?

Postby Hugh Robjohns » Fri Jul 24, 2020 7:22 pm

They can often be hired at a reasonable day rate from specialist equipment hire companies and some professional electrical suppliers... but it would probably be overkill for the OPs purposes.
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Re: Voltage supply monitor?

Postby adrian_k » Sat Jul 25, 2020 9:40 am

Thanks for all the replies guys :)

Hugh Robjohns wrote:You're in the UK, so you really won't need to worry about sustained under or over-voltages too much. And you'll know about significant interruptions because all the lights and other equipment will go off... :lol:

True, but I wondered if maybe a local factory starting up was having an an effect. Sometimes the LED spotlights in the kitchen flicker. We've always had slightly dodgy power. Until a few years back when they changed the distribution box that's on a pole on our front drive we and the neighbours were regularly getting power blips.

The reason I'm doing this is that my internet connection drops at roughly the same time every day.

That's odd... There may be some data-logging within the router that could identify the reason for the broadband outage. Worth checking. It may be an issue with the equipment at the local telephone exchange and/or some work practice there. Worth a conversation with OpenReach.

The router is the ISP supplied one and the log just says that the WAN DHCP service terminated successfully at the disconnection times. Which counters the loss of power theory because I guess nothing would be logged at shutdown in that case.

Openreach have now been and I was told the problem has been fixed. However my download speed has now halved. I got the ISP to do a line check and they say there is "still a fault on the line" so Openreach have been recalled. To be fair though the line did not drop this morning at it's usual time.

If you have (or can buy) a very cheap moving coil microphone .....

Genius! I might do it just for the crack :)

Personally, though, if you have a load of computer gear and are moving important files around -- and a NAS box suggests you might -- I'd get a decent UPS anyway. Ideally an online one, although they are expensive.

Hmmm yes I can't really justify an online one. I'll have a look at the line interactive ones, I guess something is better than nothing.

I guess that very short power outage at the the time the internet usually drops might be a complete red herring, just a coincidence.

Thanks again for all the input,
cheers
A
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