Luminescent night light

[upand_at_them]

Has anyone seen these? They're night lights that glow instead of shine like a bulb. And they use extremly low amounts of power. The one I bought says it uses 0.05watts at 120V. That's 0.4mA!

Any LED-type devices use this technology? It would be nice to have a glowing display for projects that uses so little current.

Mike

 

[Nigel Goodwin]

Has anyone seen these? They're night lights that glow instead of shine like a bulb. And they use extremly low amounts of power. The one I bought says it uses 0.05watts at 120V. That's 0.4mA!

Any LED-type devices use this technology? It would be nice to have a glowing display for projects that uses so little current.

Have you considered neon lamps?, presumably that's what's in the night lights? - 100 year old technology, and still can't be bettered today!.

 

[upand_at_them]

But neon lamps need a high voltage, right? I just wondered, since this technology looked pretty good, if there were any graphical displays that used it. 7-seg LEDs can consume a lot of current and LCDs need a backlight.

Mike

 

[JimB]

But neon lamps need a high voltage, right?
Mike

120 volts, sounds like a high voltage to me!

JimB

 

[Nigel Goodwin]

But neon lamps need a high voltage, right? I just wondered, since this technology looked pretty good, if there were any graphical displays that used it.

That's why night lights work off the mains, neons require something like 70-90v to strike. In some ways LED's are similar, both work off higher voltages with a current limiting resistor.

Somehow 'technology' doesn't seem the right word for something that old?. There have been various 'numeric' neon tubes over the years, if I recall correctly they were called 'nixie tubes' - a LONG time before seven segment LED's :lol:

 

[DigiTan]

I've seen these too. They're very thin--maybe about the size of a 3 1/2 floppy disk, and have a blue glow. Maybe this uses some kind of EL panel?

 

[zevon8]

I think maybe upand_at_them is refering to electroluminescent lighting. Basically they are made as a capacitor with a specific phosphor used as the dielectric. Apply AC and the phoshor glows. Comes in sheets, "wire" and solid panels. The common household nightlights like this give off a greenish glow like what is seen from an "Indiglo" watch face.

 

[upand_at_them]

Yes, that's what I'm talking about.

Mike

 

[DigiTan]

Okay, that sounds about right. This is the same stuff I see people use to backlight their graphing calculators. So what exactly is done to step the voltage down from 120V to whatever's required for an EL sheet? Is it just maybe a voltage divider?

 

[Overclocked]

But neon lamps need a high voltage, right?
Mike

120 volts, sounds like a high voltage to me!

JimB

Well if you want to be technical, Neons need atleast 70-90V to light.

 

[Someone Electro]

Neon bulbs need that voltage to strike.Once they start runing they can run at about 40V to 60V

 

[mahesh_jo]

light-emitting wire

Have you heard about Lytec lumi wires? its from elam Isreal and comsumes very low current. It can be used in various applications. vitis their site at www.elam.co.il.

-mahesh joshi, bhopal [india]

 

[Someone Electro]

I think these things use phosphor just like backlights.

 

[awright]

Glow panels

Sounds like upand_at_them is talking about electroluminescent panels, which zevon8 and DigiTan described above. While EL panels can be operated off the 115 VAC line, they are much more efficient when driven by a high frequency inverter optimized for the application. Typically, the inverter is optimized for the area and type of EL panel that it will be driving.

Googling, "electroluminescent panels," will provide you with 58,300 links to more than you ever wanted to know about EL lamps, including information, data, inverters and EL lamps for sale, etc.

awright

 

[atferrari]

All EL techniques

All EL techniques use AC sometimes up to 200 V with very very low current. That's why they never get even warm.

If you want to see one in action, look at your cell phone (chances are that it has one).

Just from MY experience. In the industry everybody knows that one of the worst side effects is the whining sound that those inverters could make. I, 58 yo, don't hear that but young people or just in better condition than myself, they DO. Basically for wires and panels.

Oh yes, you can also use them directly to the AC line (your risk!). They will last almost forever but light emitted would be too low and would have reasonable effect only in dark areas. (Voltage, let's say is OK, but voltage, 50 or 60 Hz is way TOO low)

Whatever you do with them, test them in the real place with the real illumination level you actually expect to have.

Buena suerte