Dimming problem

[pmcd]

We work in a village hall with eight wall lights that have been fitting with 30mA 6W led dimmable bulbs, operated by a Varilight V-Pro 1-gang 2-way dimmer unit. The problem is that with this configuration the lights will only dim to about 20%. Is there any way we can change things such that we can dim to blackout.

[p.k.roberts]

Sadly, probably not. I have some of these dimmers at home and this is about the best you can expect. I'm sure you've already looked at the relevant section of the instructions on adjusting the minimum brightness level;

 

https://www.varilight.co.uk/leaflets/V-Pro%20Dimmer%20Series%20Instruction%20Leaflet%20775.pdf

 

you might be able to improve things a bit, but I don't think you're going to get smooth dimming down to zero. That's not what they are designed for.

[musht]

Never get to absolute zero on mains dimmable LED.

 

Though some lamps are a lot better than others, particularly like Philips Warm Glow, dim spectacularly well, not sure get as big as 6W.

[Tomo]

The V-Pro dimmers are pretty good, I use them at home.

 

The problem is that your lamps are not dimmable below ~20%.

 

You will not find any mains-dimmable LED lamps that go below ~5%. None.

There are none on the market, and they will probably never exist.

 

The only LED lamps that dim below around 5% are ones that have their own specialist dimming system that takes hard power and a control signal, usually DMX.

(Note that DALI and analog controlled LED systems are usually aimed at general illumination and do not dim below 5-10%)

 

There's only three options for theatrical LED houselighting:

1. DMX to fixture
   Run hot power and DMX cables to the fixtures. Requires extra cable. Usually cheapest.
   
2. Radio-controlled.
   Easiest to install, you just need "hot power" to the fitting
   DMX/sACN/Art-Net control goes to a transmitter box somewhere in range, pair the lamps to the transmitter box and off you go.
   
3. Remote driver
   A remote driver box feeds the LED lamp circuit. DMX/sACN/Art-Net is connected to the driver box.
   

Budget and circumstances will decide which of the above three options are feasible.

ETC's ArcSystem is very nice (though I would say that, wouldn't I?) and available as either ArcMesh (2) or ArcLamp Driver (3). There are other similar systems too.

 

Many places have put up a few cheap LED-RGBW par-type fixtures and use those as houselighting for theatrical shows.

If budget is tight, that's probably the cheapest decent option.

Edited March 22, 2021 by Tomo

[A.Russell]

Tomo is quite right that using drop in dimmable LED lamps and a dimmer almost always gives unsatisfactory results. That said, the SunDial Quad from Artistic Licence was developed for just this application. I have not had any hands on experience with one (apart from seeing it on a demo), but they appear quite reasonable.

 

There is a table of fixture profiles on the website, perhaps you could look to see if your lamps are listed. Failing that they may be able to provide further advice/combinations of dimmer and lamps that work well.

 

Further details can be found at:

 

https://artisticlicence.com/product/sundial-quad/

 

(I have no affiliation with the company or product, just took note when I saw a demo!

[musht]

The issue is at other end of the cable, good as am sure the Sundial is , its value comes from its interface and load abilities,dimming principle is the same as Vari-Light, its quite costly for dimming 24W in a village hall.

 

Trying different lamps may yield better results, as mentioned Philips Warm Glow, there is a 6W , sure there are now equally as good lamps from other makers, Megaman used to be an innovator.

 

If could nail down a better user interface than a phone app, wifi bridge(?) , IoT, Smart bulbs, dim to zero , variable colour and colour temp, no rewiring needed, about a tenner each.

[alistermorton]

There are open source home automation projects out there to control those smart bulbs from PC software so you wouldn't have to use a smart phone.

[J Pearce]

I believe someone has written some scripts to control hue bulbs from QLab, but haven’t tried it so can’t make any promises - do your own research etc.