Free Standing Dimmer To Lights

[bernardgreen]

when someone just asks a simple question?

With respect the question is often simple but the answer is seldom simple.

Many here who give advice see the results of work done by people who think it is simply connecting things up in a way that works. Sometimes it is no wonder they lose patience with some people who want only the simple but then dangerous answer.

 

[PrinceofDarkness]

Oakfield: I'm truly sorry that you've taken offence at my reply - it wasn't my intention to be rude to you - but you don't really know what you're doing, do you?


Lucia.

 

[tonyelectric]

Agree with Lucia, get down to your local stage hire company and hire a little portable dimmer rack and some spots, job done, safely and cheaply.

On the linea halogen front i've been involved in stage lighting since I was at college and own quite a bit of kit, to name just two fixtures that take standard R7s 189mm tubes 750 or 1000W there is the Cremer Cycliode and Malham R7 flood (both old fixtures from the 80s) use them regularly and never had any problems with short tube life.

 

[tonyelectric]

Suitable in line dimmer, purpose made = appx £16 from B&Q

standard dimmer + backbox + glands = say £10

Then it needs testing for safety, plus they are rotary which is c**p for stage lighting.

or

roughly £10 each to hire pat tested proper stage lights which take gels and barndoors (eg: strand Patt123, QuartetF, CCT minuette) job done.

or

If your stage lighting outfit sells S/H stuff, most do, the S/H price for a CCT minuette fresnel spot is about £10-£15, tested and ready to go, you can buy a little all in one dimmer desk like a Furse Delta 8 or Strand Micro 8 for very little as well, then you have servicable kit year on year.

PM me if you want names/addresses of some good suppliers

 

[tonyelectric]

But you asked for a circuit, sorry, heres a description of a simple system (sorry scanners bust so cant post a drawing) needs 1X 2 way lightswitch, 1X dimmer and 1X 13A socket per light.

Arrange the back boxes on a wooden board in rows of 3 top to bottom, live in to common of switch, brown wire out from L1 of switch to L terminal of socket (thats your full on setting, v useful), brown wire from L2 of switch to common of dimmer, brown wire from L1 of dimmer to L of socket also, thts your dimmed circuit and on off on the dimmer.

Neutral and Earth go direct to the respective terminals on the socket unless you use metal clad fittings in which case a wire should link the earth terminals together back to the main earth at the socket.

Make sure you make provision for strain relief on the incoming cable and simply multiply this with each dimming unit as described in parallel to the mains but not exceeding 3000W total loading

 

[tonyelectric]

One caution though, the 13A sockets will only be able to supply up to the rating of the dimmer, which means if this was used by someone not aware of what they were doing it could overload, the alternative arrangement that mirrors stage equipment is to use a 5A socket per channel with a unswitched spur plate fused at 5A in line with the live of every live input protecting the switch, dimmer and socket.

Problem is you are now at 4 fittings per channel, the cost is going up

 

[bernardgreen]

Also need to bear in mind that 4 dimmers running from the same 13 amp socket ( or similar socket / supply ) may interact with each other and cause lights to flicker. This can be avoided by feeding each dimmer through a suitable suppressor / filter.

 

[tonyelectric]

Of course a simpler way on reflection, though with less control is to simply put the dimmer in line to the lamp flex after the plug (in which case live from plug to Common on dimmer, live to lamp to L1 on dimmer, N & E pass through to lamp from plug uninterrupted ) have each plug fused to 5A and plug into a gang plank (4 way 6 way etc)

good luck

 

[tonyelectric]

Good point Bernard

There was a legendary type of stage dimmer console called a Strand Junior 8, has 4 big 2' tall sliding dimmers arranged 2 channels per dimmer, you got a similar effect if you took one load off suddenly, the other load would brighten a bit. They were full of asbestos so few remain - there is one in my loft somewhere with all the other obsolete c**p i've saced over the years!!

 

[bernardgreen]

4 big 2' tall sliding dimmers arranged 2 channels per dimmer

Nostalgia,

"" Don't put all the lights up or the incomer will blow "

The old sliding rheostat controllers were good for keeping the meat pies hot until the interval.

One of the first solid state thyristor switching stage lighting units had to have filter coils fitted rapidly as an after thought when the dress rehersal showed a design fault.

 

[ericmark]

I got my plug in dimmer from Lidl but one should not really dim a halogen lamp.

Of course one can DIY and one could use a brine bath and electrodes but today I would think the HSE may have something to say about such a dangerous process. Well I will rephrase. I know HSE would have something to say like your court appearance will be on!

As one moves from the silly and dangerous to the propriety hired stage lights there must be a demarcation line but where this falls I don't know.

Much depends on the insurers and what they will allow and by time one has written to them and got an answer likely it will be too late.

Rule of thumb is if you can plug it in then likely there will not be objections but if it needs some assembling then likely not permitted.

The plug in dimmers I have would be far too hit and miss for a play. One presses on and they come on then press on again and they slowly go from max to min and pressing again fixes the light level. Pressing off switches off and pressing on again returns to level set before switched off.

They say 3Kw but I would not like to try using that much power. Think it refers to the pair of switches in the pack. It had two dimmers and two plain on/off in same pack with remote.

Many years ago we staged the Gang Show with the scouts. At first we used a small primary school and we did have problems when the lighting overloaded the fuses. My father was franticly trying to re-wire the fuse while the compare asked the audience to lift there arms into the air. As many hands make light work? However this 1960's production did point out the dangers and the next year we moved to secondary school where the lights and stage was all pre-set.

It turned out to be all due to someone who's kid was in the production plugging in their cine lamps 3Kw which overloaded system. However careful one is some one some where will do the unexpected.