constant dim glow of 240V LED lights

G'day all,
My client ended up buying a few 240V LED brick lights due to price and looks of the light, which are now installed. These lights are connected to a channel of a 2amp dimmer module as i thought the client would just get the standard 240 globe brick light. My problem now is that they glow ever so slightly due to voltage leaking from the output.

One solution that i have is putting a 2uf 400v mains cap across the N and A of the chn (load)... but not 100% sure if this will a long term affect.

I'm stuck at the moment as the system has no free relay chn either. Only if i had my thinking cap on before i chased in the lights. Any one got any ideas??????

 

A similar thing happens with low-wattage Compact Fluoro lamps, if there's only 1 per dimmer channel. We had a few in our showroom and even at zero a couple of them still "kind-of" try to start and run !

You could hide an incandescent load somewhere (although what happens when the lamp fails?) - perhaps gang the bricklights across to another circuit (say a downlight somewhere in the area, or even convince them that they need a downlight...).

John

 

G'day John,
I like your idea....Even (maybe) a 2500 ohm 10watt R might be as good. That is if it doesn't heat up and go open cct or even worse a dead short. The only problem is now most clients like to have more and more control and flexibilty over thier systems...

I was hoping to use these bricklights on a sun switch set-up originally, which would be set to recall 1 and ramp up once the PIR picked up movement or if the access control system had a valid entry.

 

Hmmm.... I have 140+ of the things - 9 watt each - and all on 1A (8 channel) dimmers. Some have just one or two lamps on a channel, the most would be 10 on a circuit. I've not noticed any problems. (Yes, I know I shouldn't be running them on dimmers - but I wanted the facility later to replace them with LEDs, or halogens if the CFLs didn't work out).

The ones I have are Megaman, and they're drop-in replacements for the GU-10 240V halogen lamps in cosmoluce (?) downlights.

Their only real down-side is they're pretty dim for the first minute or so until they warm up, but then they're fine. Good even light, minimum shaddows, low power consumption (ideal when you're on solar power) and don't generate so much heat.

RossW

 

Hey Mrava,

How about stuffing a Single-channel relay in there somewhere? Code 5101R is only 109.80 list trade

We often use those to solve the common "bummer, they want a few extra channels" problems - and they fit nicely down the side of a 15-pole enclose next to the 12-pole C-bus modules (they usually can just be bolted onto the din rails, or make a small plate)...

And not even as expensive as the bricklights would have cost them

 

That's good to know - the ones we had problems with were Osram 21w E27 base, using 1 per 1A channel. And what is wierd is that it only affected SOME of them (they were all in a row, matching lights in different colours in a lighting showroom)

Cheers, John

Edit to add PS : Cosmoluce are the agents for Megaman lamps, but I've also seen them at Gemcell Electrical Wholesalers.

 

Just put in a relay operated off the Dimmer ... I assume you don't want to dim the lights as you mention that you have no free relay channel.

Regards, cc&c.

 

2uF cap works

Guys,

I've put a 2uf 400V cap across the dimmer output for a day and it seems to work ok. The only problem that i've come across so far is that the light stays on 1 -1.5 sec after turning the output off due to the cap discharging. Will experiment with the diming limits of this under load for a few hours

 

Dimming of LEDs - watch out !

Hey - just a thought...

Be careful with dimming of LED's - it is NOT as simple as it appears !

LEDs use a constant current Driver device to run them them (rather than a transformer which is "constant voltage" as used for incandescent loads). The reason being that the LED device doesn't self-limit it's current, and the brightness you get from them depends on the amount of forward CURRENT across them not by varying the voltage.

So, it depends on how the LED Driver device reacts when wave-chopping dimming is applied to it.... some of them (generally the cheapy ones) will probably dim OK, but any decent quality LED Driver will not act as expected when fed with a mis-shapen 240v waveform, and will continue to apply full brightness even when (RMS) voltage is varied.

LEDs really should be dimmed using a proper dimmable Driver device and 0-10V Analoge or DMX or similar protocol.

That's the theory anyway.

But it might just work OK for those cheapy (chinese?) bricklights - they probably have a very simple driver in them that just drops the voltage which is technically not correct but will work long enough for the warranty (if any) to expire

 

Osram LED transformer

John,

Your proberly right..... Might be best to hold these dimmers at 100% only. My concern is more so the long effects on the dimmer module. These bricklights are for sure these asian babies that will prob. rust in the next year or so. (Warranty expired when the client walked out of the store i reckon)

Osram have a nice transformer for LED lights and basic colour mixing trannies for LED.

 

For the record, VS Lighting (Vossloh Schwabe) have some nice offerings too. Apart from the normal LED modeules, strips and controllers, they also have some cool 12V plug-in units that replace a standard 12v Dichroic in a LV downlight !

Cheers, JC