Mains LED

[Sargan]

I bought a 30W rechargeable work LED

While there is no doubt its bright if you look into the light, its not that good as a work light - certainly poor compared to an old square florescent tube work light These however are not rugged and don't last long.

Anybody able to recommend a good mains powered LED work light, needs to be rugged, but does not need rechargeable feature.

[wrights...]

I normally use a good quality head torch. Much better than a fixed light as the light is always where you want it. No shadows. Ledlenser H7R SE Bill

[Sam Plusnet]

I use a head torch plus a Makita 18V 'Flashlight; (actually a low-medium powered worklight).

For some jobs, placing the worklight at an oblique angle to the surface I'm working on helps to show up the fine detail.

[Sargan]

Have one of those, but also need to light up an area.

[GB]

Something like this?

NB You may need a 240v version.

[Brian Gaff]

Well of course not, as LEDs are by nature one direction. There are two work around, but neither are efficient. The first is to use a UV LED and a phosphor system of some kind, as this does tend to be more defuse. 2 Multiple Leds, pointing in different directions. However you look at it, sorry, you are throwing away the light in the other directions to the forward beam, and the more you defuse it, the more current it will take to give the same light output over the wider angles.

Brian

[Mike Rogers]

What do you expect from a battery powered light which costs a third the price of the mains powered florescent light?

Mike

[whisky-dave]

How is that relevant, as yuo can just have 2 LEDs back to back. But when working from 50Hz you might see more flicker than you would with a incandescent or fluorescent light.

why would they need to look in differnt directions.

But it might balance out , an advantage of LEDs is that they are more easily dimmed.

>

[Paul]

Capacitively coupled LED lamps, have a full wave rectifier, so in this example, the LED flickers at 100Hz. There are two capacitors. On the AC side, is a capacitor ("capacitor dropper"). On the DC side, a capacitor filters off the flicker. It depends on phosphor persistence (blue light to white light conversion step), as to how much of a persistence-of-vision effect results at the LED level itself.

The capacitor method is only practical at low power levels. This is why the Dubai lamps stop at a low power, as they're capacitor type, but they also include a small transistor-based regulator circuit, to handle some mains variation. Cheaper capacitor dropper, can be blown by voltage transients. Even a Dubai can be blown, just not as easily.

*******

The cheap screw-in lamps today, have an SMPS (SEPIC or CUK or flyback), and the output is flat and clean DC. The output is regulated to within an inch of death. There will be no flicker from the SMPS. As mains voltage varies up and down, light output remains constant. However, the dimming feature can be less than clever (unfortunately), which can lead to all sorts of effects. You can buy un-dimmable ones, if you want a very calm light in the time domain. Even an un-dimmable one, can use a controller which is dimmable but the dimming feature was <cough> turned off.

SMPS lamps can have acoustic "coil noise". A box of lamps I bought recently, about half of them have coil noise, the other half are fine. It's not loud, but it is annoying. Normally when you design power conversion processes, you aim for 25KHz or higher, but some schemes also have a 200Hz component, and then there could be artifacts or excitation of mechanical effect in the coil.

This one, is a wide-range street lamp (world-compatible).

LEDs in bulbs, can use string-o-LEDs ("filament" type) or can use individual LEDs on an alumina substrate (the LED flood next to me does it that way).

High power LED arrays, some of those run at 40V, and you could use a couple of those, off that street-lamp circuit. Those are bright enough to "knock an eye out". Array lights are about one inch square (covered in LEDs), and the phosphor forms a yellow (conversion) coating over the entire surface.

Buck converter circuits (voltage reduction) are available as constant current sources. If you know what DC current a LED can handle (350mA on the high power star ones), you can run an arbitrary series string of 350mA LEDs off a "buck puck". You could arrange a wall adapter (clean DC), a buck puck, and LEDs arranged in series (up to the limit of the available DC voltage). The current source behavior of the buck puck, prevents the LEDs from burning out on over-current.

*******

Retail LED panel lighting that runs off mains, could be arranged as a portable light source, but you'd have to DIY the packaging to make it practical. Many posters here, have panel lighting in the shop or in an out-building.

My bicycle is an example of panel lighting, in that the front lamp uses 48 LEDs and the rear lamp uses 48 LEDs. If the tiny LEDs have individual plastic lenses on them (15 degree), the light "blends" into a circular lighted area (even though the LED PCB layout is rectangular!). The other advantage of array lighting, is if cabling is in the way, the shadow of the cable is not thrown into relief like a hand-puppet on the wall, and the shadow of the cable is blended out too.

*******

The box the lamp comes in, has a CRI value printed on it. There are just enough truly awful LED sources, to be reading the CRI off the box. CRI as a single-point specification for white lamps, isn't the best, but it is intended to allow selecting lamps without seeing their light in person. At a builders merchant, sometimes they have several lamps side by side, and you can see significant differences in how pleasant the lamps are. And that makes avoiding the harsh ones easier.

Some lamps aren't even eye-safe!!! Be wary of LED floods with fresnel lenses on the front. Don't shine them towards yourself while working. With a flood like that, bounce it off a ceiling and avoid line-of-sight usage. I ended up with spots on the retina from one of those, which took until the next day to blend out.

The flood sample next to me, does not use a fresnel, and the CRI is bloody amazing - the lamp has light, which is the spitting image of an incandescent bulb (and it's not even using any "tricks" to do it). These are, of course, no longer for sale. There have been a few lamps in the past, that I would actively seek out, if they were still for sale. All we're left with, is cheesy ones.

In terms of ruggedness, some of the modern cheap screw-in LED bulbs, the printed circuit board inside the unit is an "interference fit" to the electrical contacts. They don't use solder on those connections. If such a lamp is dropped, it might upset continuity. The "LED filament" lamps (filaments in space), might not be able to take a 1000G mechanical shock. There is still some need for care in selecting a work light type. The housings of some modern lamps are fraught, and too cheap. If the envelope breaks, there is mains potential inside there.

It's harder to electrocute yourself, with a LED flashlight, if working in a water flood. That's at the 3V level. Using a lamp running off 56V DC pack while standing in water, might be hazardous to your health. HV DC is nasty stuff.

Paul

[Sargan]

I expected it to be better is the answer :-) With the now maturity of LED expected it to at least match the Fluorescent.

The Fluorescent are good at providing a working light, but too fragile.

[Theo]

You may f "We owned a factuary which is specialized in Flannel Authentic Animal Onesies, Costumes, Kigurumi, Home Garden, Auto parts production for over 10 years!"

I'll be sure to make that my first choice next time I need brake pads.

Theo