To UPS or not to UPS?

[DJ Jules]

I've never considered running my kit off a UPS before in the 14 years I've been DJ'ing but, so far this year I have had 6 DJ gigs and the power has cut out at 3 of them :facepalm: Last night I discovered the venues main sockets are fried and don't make a reliable power connection. Unfortunately, I discovered this in the middle of the first dance.

Anyone bother with a UPS? Which bits do you protect?

I have a flight case with laptop, dmx, wireless DMX transmitters, USB hub, Denon controller and wireless mic receivers and I'm thinking that one small UPS ought to be able to run them for a while (the total power draw is probably less than 80w). I did think that switching one of the 12v power supplies for a battery backed supply would be cheaper/lighter/more efficient as it'd keep most of the case alive, and then I remembered the Denon has it's own power supply.

Open to ideas...

Julian

[Excalibur]

On the assumption that some form of lighting remains, although mine would die, if I were using the Maui GO, my laptop and VMS would continue for a while. The idea of an UPS is very appealing nonetheless. I don't have any, but battery uplighters would improve life even more.

[Nakatomi]

Funnily enough Julian I've been looking into buying a UPS recently - not for just any old power cut scenario though... for venues with a limiter!

If you're only looking to keep your playout flightcase 'up' with a total draw of under 100W, a bare bones UPS of around 500VA would keep your stuff juiced up for quite a while. I've tried looking into what the VA ratings actually equate to in terms of run time but all I could find out was that a typical 500VA UPS will be good for long enough for a computer to safely shut down - a couple of minutes or so. If that's with 500VA (500W if the power factor is more or less 1 - it won't be far off) then you could expect it to keep your stuff powered for half an hour at least.

A while back I measured what my rig pulls from the wall (minus hazer) going flat out (RCFs weren't quite hitting their limiter) & it was about 830W all told. To keep that going flat out long enough for venue staff to reset their limiter I think I'd need something like a 1500W UPS - though if I know there's a limiter in the place I'd hardly be pushing my PA much so maybe a 1000VA UPS would do the job. Then again, not only does it need the capacity to keep things running a while - it also has to be able to recharge in time for the next outage. Buying more capacity than you need will help there.

EDIT:

Oh - and be very very careful with venues where power is intermittent, especially when it comes to powering everything back on. Try not to let everything come back on at the same time. A few friends of mine have had kit go faulty because of unreliable power at venues - unexpected unpluggings & all kinds of things. Infact if you don't already have a sequenced power-on regime at your gigs I'd strongly advise you start.

I turn on my playout gear first (laptop, controller etc) then each speaker in turn, then lights, then haze etc. The reasons for this are many but mostly because of what's known as 'inrush current'. What this basically means is when a thing first has power applied to it, internal power supplies can draw a large instantaneous current from the mains for a very brief period. Enough of these at the same time can make the voltage at the socket you're drawing power from dip enough to cause havoc. I've theorised (and as yet haven't proved) that this dip could confuse equipment with auto voltage switching (110 to 240VAC) inputs - hence all the tales of speakers going BANG literally the moment they're plugged in or switched on.

IN THEORY suddenly disconnecting your gear from power while it's going flat out SHOULDN'T harm anything. It's what you do when the power comes back on (even momentarily) that could make the difference between it surviving or not.

Second edit:

Before anybody mentions power conditioners - they're certainly an interesting idea but for my money the jury is still well & truly out on them.

Surge protection offers you only so much grace from nasty mains spikes etc - try to buy a power strip which has an indicator telling you the surge protection devices are still working. The little varistors they use inside can only take so many hits & then they silently fail - leaving you with no protection at all ;)

[Excalibur]

Funnily enough Julian I've been looking into buying a UPS recently - not for just any old power cut scenario though... for venues with a limiter!
The evil :Censored: in me really fancies watching the faces of the venue when the power goes off, and the Mauis keep singing cheerfully. :D



Surge protection offers you only so much grace from nasty mains spikes etc - try to buy a power strip which has an indicator telling you the surge protection devices are still working. The little varistors they use inside can only take so many hits & then they silently fail - leaving you with no protection at all ;)

A colleague was devastated to find that the blighters aren't indestructible! The thought of them being almost " single use " was too much for him to bear. :eek:

[DJ Jules]

I guess my goals are two fold.... Keep the lights on (I have battery uplighters and I'm often the only light source in the room) and minimise the time for recovery (I think most people understand that when the power goes off, things stop, but it's the minutes where I have to reset the dmx software and wait for the Denon to boot and Windows to recognise again that are the issue).

If I powered my flight case then the sound would go off, but would return as soon as power is restored, but uplighting and the freedom sticks would keep going. Moving heads, stratospheres, etc would obviously all go out.

I don't really want the extra weight of a decent 1kva UPS :) I do wonder about rethinking the power for the Denon. If I could run that off a 12v rail then I could use a li-ion battery pack instead of a UPS, which would be a substantial saving in weight and size.

Julian

[Nakatomi]

What voltage does the Denon run on? My mc7000 has an awful 4 amp 5 volt plugtop adapter (aka wall wart) which I decided to bypass in my console. I just bought a 5 volt 5 amp power supply & did my own mains wiring inside the console. I'm sure you'd be able to find a suitable converter to adapt 12v to whatever the Denon needs.

[DJ Jules]

What voltage does the Denon run on? My mc7000 has an awful 4 amp 5 volt plugtop adapter (aka wall wart) which I decided to bypass in my console. I just bought a 5 volt 5 amp power supply & did my own mains wiring inside the console. I'm sure you'd be able to find a suitable converter to adapt 12v to whatever the Denon needs.

I think (from memory) that the wall wart is 12v 3A. I'm not 100% sure now why I put it on it's own power supply (I have a 12v 5A power supply in the case running a USB hub, 2x mic receivers, and a Chauvet DiFi transmitter via a voltage regulator). I have a feeling it was because I wasn't sure quite how loaded the supply is at the moment (it used to run the VMS before I switched to Denon, but the VMS could be USB powered). I might have to revisit that and see what the actual load is...

12v Li-Ion packs with 27ah batteries are quite common, but the chargers are rated at 2A on the ones I've seen (despite max output being 6A!) so I'd need to be careful with limits.

Julian

[Excalibur]

(it used to run the VMS before I switched to Denon, but the VMS could be USB powered). I might have to revisit that and see what the actual load is...

The VMS technically isn't USB powered, but if the laptop battery is in good condition, it will actually run from the USB. This can lead to interesting situations, when you find the only thirteen amp socket in the room that doesn't actually have power. The laptop fires up, the VMS loads and plays, but your lights and amps don't work. You then start checking the power to the lights, because obviously, the laptop and VMS have power, don't they, they've lit up? :daft:

[rth_discos]

How many plugs are you running this off?

At the very least, the haze should have its own socket, away from the rest of the disco.

You'd be looking at a pretty powerful (and heavy) UPS to provide you with any meaningful power contingency for the load of a disco.

[DJ Jules]

How many plugs are you running this off?

At the very least, the haze should have its own socket, away from the rest of the disco.

You'd be looking at a pretty powerful (and heavy) UPS to provide you with any meaningful power contingency for the load of a disco.

Yup... That's why I'm not thinking about running the whole disco off a UPS, just enough so that the battery dmx lights stay on and when the power comes back on, I'm not waiting for controllers to reboot and having to reset software.

Julian

[rth_discos]

Yup... That's why I'm not thinking about running the whole disco off a UPS, just enough so that the battery dmx lights stay on and when the power comes back on, I'm not waiting for controllers to reboot and having to reset software.

Julian

But are you already running the haze off its own socket?

I stopped using haze - mainly because of the risk to setting off fire alarms, but also because it was the one item that would trip electrics. Have you tried not using it and seeing if that fixes the problem?

[DJ Jules]

I've had issues with power for a variety of reasons : sound limiters, fire alarms that are wired to cut the power to entertainment, catering equipment tripping supplies and, in Friday's case, a socket that has taken some abuse and has a poor connection to whatever is plugged into it.

I rarely use haze. Where I do, it's usually positioned off to side or at the back of the room to fire the haze towards the lights and that usually means it's on its own plug anyway (and controlled via wireless DMX). The actual power requirement for my haze machine isn't that much (600w), but it is an inductive load as it's essentially just a compressor and has no heating elements. I'd never put the haze machine on a UPS though, it's just not an essential part of the show.

I'm leaning towards adding a 12v Liion pack to my flight case instead of the power supply I have at the moment. The challenge seems to be finding one where the specs are reliable and I can trust the power ratings for the outputs... I also don't seem to be able to get a straight answer from anyone about whether the wall wart could be swapped out for a 3rd party supply or if its actually part of the constant current/charging system and I run the risk of overcharging the batteries if I switch it for another.

Julian

[Nakatomi]

I've had issues with power for a variety of reasons : sound limiters, fire alarms that are wired to cut the power to entertainment, catering equipment tripping supplies and, in Friday's case, a socket that has taken some abuse and has a poor connection to whatever is plugged into it.

I rarely use haze. Where I do, it's usually positioned off to side or at the back of the room to fire the haze towards the lights and that usually means it's on its own plug anyway (and controlled via wireless DMX). The actual power requirement for my haze machine isn't that much (600w), but it is an inductive load as it's essentially just a compressor and has no heating elements. I'd never put the haze machine on a UPS though, it's just not an essential part of the show.

I'm leaning towards adding a 12v Liion pack to my flight case instead of the power supply I have at the moment. The challenge seems to be finding one where the specs are reliable and I can trust the power ratings for the outputs... I also don't seem to be able to get a straight answer from anyone about whether the wall wart could be swapped out for a 3rd party supply or if its actually part of the constant current/charging system and I run the risk of overcharging the batteries if I switch it for another.

Julian

My guess would be that charging control will be dealt with by electronics inside the pack. Companies don't tend to design their own power supplies these days - it's much easier just to buy something in that's already tested to whatever standards & approvals.

But that's just an educated guess. The reality could very well be different & I sympathise with your doubt ;)

[DJ Jules]

My guess would be that charging control will be dealt with by electronics inside the pack. Companies don't tend to design their own power supplies these days - it's much easier just to buy something in that's already tested to whatever standards & approvals.

But that's just an educated guess. The reality could very well be different & I sympathise with your doubt ;)

I'm struggling to see how the wall wart could discern between power going to charge vs power running the connected devices so it'd be impossible to manage the charging process (pretty important with liion cells).

But then the wall wart is 12.6v which is oddly specific...

I might just buy it and see. If there's a charging indicator on the wall wart then I might have a problem.

An interesting side effect of this project is that I'd have a limited show that I could run without mains (Maui5 Go, battery pars and freedom sticks with wireless mics, controller and wireless DMX) and with just a single cable from the Denon to the Maui5... The weakest link would appear to be the laptop battery!

Julian

[rth_discos]

Yup... That's why I'm not thinking about running the whole disco off a UPS, just enough so that the battery dmx lights stay on and when the power comes back on, I'm not waiting for controllers to reboot and having to reset software.

Julian

My DMX runs off my laptop - I run Freestyler DMX

On the odd occasion where I have lost power (usually due to sound limiters), when the power restores, everything springs back to life immediately and carries on as if nothing had happened.

But if you are intending to run just low power stuff through the UPS (essentially, everything except the actual lights and the speakers), then you won't have any issues, especially as most outages are considerably less than a minute.

[DJ Jules]

My DMX runs off my laptop - I run Freestyler DMX

On the odd occasion where I have lost power (usually due to sound limiters), when the power restores, everything springs back to life immediately and carries on as if nothing had happened.

But if you are intending to run just low power stuff through the UPS (essentially, everything except the actual lights and the speakers), then you won't have any issues, especially as most outages are considerably less than a minute.

All of my USB devices run from a powered USB hub and the Denon runs off its own adaptor so, as soon as I lose power, everything disconnects and the Denon resets so it takes a little bit of time and a few button presses to get back up and running.

Powering just the Denon and the hub from a 12v UPS would keep things running while the power is off.

Julian

[rth_discos]

This came up on my Amazon recently, and looks ideal for what you need to achieve:

https://amzn.to/3HXu0p8

[ppentertainments]

This came up on my Amazon recently, and looks ideal for what you need to achieve:

https://amzn.to/3HXu0p8

That is the one I use and does the job. Avoid cheaper / lower powered ones