is it possible to get a Battery to power A LED for a LONG time?

[MrAl]

Hi again,

Ok so you are saying about 0.4 lumens, that's sounds good. I remember back then the LEDs barely lit up, just enough for an indicator light.
It's really amazing what we used to call an LED back then !

I had an interesting red 3mm 'hat' style red LED from way back in the 70's that would 'glow' bright red when i pointed a modern laser directly at it. It looked like a laser too when i did that. No other red LED ever did that, only that one. Not even sure if i have it anymore though.

 

[Tony Stewart]

Actually Lumens has nothing to do with brightness from the eye, it is measured by the volumetric sphere.

I ship LEDs with 16,000 mcd in 30deg minimum and more than double max. and 10,000 mcd 30deg in Red Yellow worst case minimum

Here is a typical old GaAs Red 660nmD 60deg diffused 5mcd **broken link removed**

The ratio is 3,200 in Iv. or Luminous Intensity. The reason they may have looked better than this ratio is the diffusion increases the size of the source from 1.5 to 5mm and diffuses the light.

But these 5mm LEDs I get, are unsafe at short range for long durations and painfully bright.

 

[MrAl]

Hi,

Actually I use the basic idea of the integrating sphere. For a casual conversation and unknown LED i use 1/8 of the sphere surface as a very rough estimation of the beam angle illumination so that for a given brightness we can get a rough idea of the lumen rating. For an angle 2 times greater than that then the lumens goes up by a factor of 2, but it's just an estimation that i dont intend to be super accurate.
If we knew the beam solid angle we could get much more accurate.

 

[Tony Stewart]

Yes 1/2 angle is 2x Iv intensity minus 10% lens loss each octave roughly.

Beam power angle is always 50% peak but not always Lambertian or same ratio at other % offsets, yet our eyes are logarithmic... So 10% fringes off axis are glare to some apps.

... and I wish they would show polar plots in log but transparent substrate reflector cups are not perfect and tolerances would look bad in log scale but more realistic if there is side glare.

But i digress....

 

[stevensrd1]

Actually there is a way to power led lights for many years. If you use a home made water battery. I have used them for many many years powering low current devices such as led lights, motorized rotating stands, wall clocks and so forth. I made videos on how to make these water batteries **broken link removed**

 

[atferrari]

Prior you introduce any over unity concept, please give a link where the water battery is explained. A brief concrete explanation is much appreciated.

 

[Tony Stewart]

A chemical battery is possible with highly reactive material like Magnesium in water but this is hardly over unity. such attention seeking , non scientific demonstrations are lacking the scientific approach to measurements. Oxidation of surface adds resistance , so cleaning is needed. activity is proportional to current. In extreme cases they used Magnesium salt water activated batteries to propel DC motor torpedoes during WWII Battery life span was very short but 50A batteries were made.

**broken link removed**

 

[JimB]

Thread closed
JimB

I have closed this old thread and started a new one here:
https://www.electro-tech-online.com...r-an-led-for-a-long-time.152953/#post-1317225

The old thread was re-awakened by a new member with a slightly different problem, a different problem is better in a thread of its own, then there is no confusion which problem is being answered.