12/24V dimmable LED "bulbs"

[Shez]

I'm currently looking at a project to build some traditional looking "shell" type footlights. For various reasons, I'm leaning towards LED rather than tungsten - not very traditional I know! Rather than suffer the potentially steppy dimming of using 240v lamps with mains dimmers, I was hoping to be able to find 12 or 24 volt "bulbs" with standard-ish connectors that would fit in d0mest1c holders - BC, ES etc. To be driven by proper DMX LED drivers - LTECH or similar. A niche market of course as plugging them in to a normal (physically compatible) mains outlet would fry them.

 

Short of a few (expensive) marine applications, my searches haven't produced much. Has anyone found anything for this sort of application? Essentially just a bare LED source with no electronics inside a globe. The exact form factor may not be critical here as they'll be mostly hidden behind the shells but it would be nice if they looked at least a bit like an actual bulb. Warm white of course. And budget friendly.

[alistermorton]

Have you tried dimming the small, bi-pin 12V lamps used for under cabinet lighting? I've no idea if they'll work, but they're cheap enough to experiment with. You might get lucky and find they just use a resistive dropper, although they're probably wired as two opposed series strings, one for each half cycle, so you might only get about half brightness.

 

Edit It's G4 bulbs I'm thinking of. The better ones are regulated, which in this instance you probably don't want.

Edited May 19, 2020 by alistermorton

[Gnome]

Aten Lighting in Melton Mowbray produce 12 and 24v LED lamps, some in traditional form factor. They supply to the heritage rail market and others where mains is not available. Not sure about dimability.

 

https://www.atenlighting.co.uk/

[J Pearce]

I've had success with the cheap and simple G4 capsule lamps and LED tape drivers. You need to ensure the G4s are dimmable (some use a switching supply for the LED rather than resistive dropper), but other than that works great. Keep toying with trying to make some birdies with them, as I have some spare birdie shells without transformers, planning to nick PAR16 reflectors off dead lamps to make a raylight type shell to take G4 lamps.

[martinw]

I tried and failed to find what you're looking for either at 12V or 24V. I auditioned various BC and ES low voltage LED lamps to dim using a PWM LED dimmer, but the lamp's internal electronics always got in the way and resulted in a flickery mess. I ended up making my own lamp using some of these LED filaments soldered to a wire frame. I'd still like to find a better solution as I can see this is something I'd need more of in the future.

 

Martin

[Shez]

Have you tried dimming the small, bi-pin 12V lamps used for under cabinet lighting?

No practical tests yet - just researching thus far.

 

I've had success with the cheap and simple G4 capsule lamps and LED tape drivers. You need to ensure the G4s are dimmable

 

The G4 option does look like the best bet. There are some interesting side fire disc assemblies available - might be possible to bypass the onboard regulators on them. I've seen some more bulb shaped designs but most appear to be IP rated so would be less easy to customise. Possibly an option to fit some kind of bare COB with pins to fit that G4 socket.

[Don Allen]

I bought some G4 LED lamps to try as step lights for retractable seating, but they were too long compared to the Philips 12V 10W G4 halogen lamps fitted and had narrower pin spacing. Had to stick to the Philips as the lamp bases were positioned so the top of the lamp was up against the slotted faceplate.

 

You will need to check the focal point of your reflector if you are going to put them into birdies.

[J Pearce]

I've had the G4s in all manner of oil lamps, gas lamps, electric lamps, and built into prop candles so as to look like a flaming wick - looked great on a period chandelier.

 

Straight into a LED tape driver, some G4 lamps need correct polarity, some don't. Dimming curve is tolerable, but we're only using the cheap drivers at the moment. An upgrade is on the to do list considering how much we use them. I have wired them in series before when full brightness wasn't needed to move that snap on down the dimming curve a little.

 

I've also used them wrapped in gel in fireplaces - 3 circuits off an RGB tape driver. Each circuit has red, orange, and yellow lamps, spread them around under coals/firewood, chase the 3 circuits and you get a lovely twinkling fire.