LED bulbs intermittent lighting?

fthanron · by **fthanron** » 02/02/08, 09:55

Hello (well, the report Isolation wadding is cool),

For following various readings about lighting, I ask myself a few questions ... it does not change much;)

In fact is it imaginable lamps led to intermittent lighting (or does it exist ..?)? The human eye only perceives a limited number of frames per second so maybe if the lighting is sync with our eye, we would see no difference with continuous lighting? What do you think ? Would an energy saving and an increase in the life of the bulbs also flow?

Same for growing plants under lamps? (not in relation to the vision but to the capacity of absorption of the photons / creation of matter)

Thank you the engineers in advance!

Sincerely yours.

Christophe · by **Christophe** » 02/02/08, 10:21

Uh correct me if I say bullshit but it seems to me that this is the case with incandescent bulbs supplied at 50 hz .... they "flash" at 100hz ...

For the LEDs I think it would be more detrimental to their lifespan than a real gain ... especially given the potential "gain" ...

Leo Maximus · by **Leo Maximus** » 02/02/08, 10:26

LEDs allow intermittent pulsed lighting. See my 8 / 11 / 06 post in: https://www.econologie.com/forums/un-eclaira ... 51-10.html
I get much better lighting than the classic 2,4 watt lamp with 0,1 watt only. Another advantage: the LEDs can withstand a much higher current provided that it is in the form of very short pulses, nominally 20 mA pulse it supports 100 mA.
Pulse, LED or tungsten lighting is not new and there have been many diagrams published in the electronics press with many variations, for example, one can vary the light intensity by playing on the width of the pulses.

Christophe · by **Christophe** » 02/02/08, 10:29

Mea culpa Maximus Leo!

But in this case what is the life time?

Leo Maximus · by **Leo Maximus** » 02/02/08, 10:35

Christophe wrote:Uh correct me if I say bullshit but it seems to me that this is the case with incandescent bulbs supplied at 50 hz .... they "flash" at 100hz ...
For the LEDs I think it would be more detrimental to their lifespan than a real gain ... especially given the potential "gain" ...

It is highly likely that the LED bulbs operate from a rectification in alternating mode so not in 100 Hz but in 50 Hz single alternation where visible blinking, especially on the edges of the visual field. There are lamps (particularly bedside) that have two lighting intensities, the low intensity position of the switch switches a diode in series: it lights less but it blinks.

Christophe, the pulse operation does not reduce the life of the leds, the leds are made for that.

Leo Maximus · by **Leo Maximus** » 02/02/08, 10:49

Christophe wrote:Mea culpa Maximus Leo!
But in this case what is the life time?

The white LEDs are given for 100000 hours (one hundred thousand), provided that the conditions of use are respected. For a standard white led it is 3,2 to 3,4 volts and 20 milliamperes. These conditions are NEVER met in the countless light gadgets made in the middle empire. The leds are supervolted, suddenly it lights up super, it's great, and it goes wrong after a few hours and we say "the leds are m ..., it's a trap for c ..."

The best white leds are the Nichia (the inventor of white leds), most of the others are counterfeits including those made by Siemens and Philips in China under different brands.

fthanron · by **fthanron** » 02/02/08, 10:59

So if I understand from you Maximus Leo, LED bulbs already use pulsed lighting!

(Thank you for enlightening my lantern because as far as the electricity is concerned it's been too long since I have not granted a piece of brain ..;).

Can you provide some links to these bulbs with two intensities? Have you tested? Comparison with the existing incandescent? ... O ;-)

Christophe · by **Christophe** » 02/02/08, 11:02

Pkoi led bulb manufacturers do not use this property because according to you for the same lighting you can reduce consumption by 24 and increase the life ... so I have trouble understanding why c is not applied ...

It's to sell crap and renew the gear faster? It's really taking buyers for cons ... but hey it would not be the 1ere time ...

Leo Maximus · by **Leo Maximus** » 02/02/08, 11:13

fthanron wrote:So if I understand from you Maximus Leo, LED bulbs already use pulsed lighting!

I did not say anything like it, it must be a mono-alternating recovery, it's a half-sinusoid not an impulse.

fthanron wrote:Can you provide some links to these bulbs with two intensities? Have you tested? Comparison with the existing incandescent? ... O ;-)

I did not mention two-intensity bulbs, either : Lol:

These are bedside lamps that have a switch to 3 positions: 1 / OFF; 2 / on with normal lighting; 3 / on with attenuated lighting with a diode in series, it blinks a little is normal, in fact it is good 50 Hz but there is only half of the sinusoid.

fthanron · by **fthanron** » 02/02/08, 11:17

Ahah was right, I warned that my interpretation of the information might be in the west! O)

Well, what about those manufacturers who do not care about us or what?

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LED bulbs intermittent lighting?