At what frequency does the human eye notice flicker?

Low current as compared to higher current, empirically, e.g.

See also

Okay but I don’t what the red line is representing? or the dashed line.

Good link Hank! Thank you.

The article discusses modifying the waveform to compensate for an AC circuit.

This is interesting because the AC mimics the on/off pwm this thread is exploring. What I find even more interesting about that article was the proposed change from 120mhz to 150mhz the EPA tried to mandate
because of a known negative effects or sensitivities that humans experience at ~ 120mhz.

Weaponize an LED’s in this frequency range? Isnt that the same frequency (120 mhz) that LED T.V.’s utilize for rendering high definition 1080P?

Okay that will make a great topic for another thread!!!

I knew there was some kind of relative association that exists.

Okay I need to think on this more so I can construct my questions from another perspective.

i can see 120hz flicker in cheap n nasty bulbs.
and cant stand low refresh rates in old crt pc monitors.worse when it beats with other lighting.which in the store was 4 tube t12 magnetic troffers.when we had pc’s on display at the shop i had to go around and reset all of them.otherwise it was like a room of strobes to me.
nobody but me and our tech could see this. this varies by the individual and reading that link also whether they have cirrosis.which i do not.

We have?

Not on my oscilloscope! :smiling_imp:
The resonant frequency of DC is zero.

lol. It would be a matter of semantics at this point.

I like you guys.

DC Current doesn’t resonate or pulse. Read again the first line of the Wikipedia article you linked:

We do see some resonance in our drivers at times, showing up as ringing. DEL told us how to fix that, so it shouldn’t be a problem with any of the newest drivers developed by PD68, TA, and others. :smiley:

My apologies if I sound rude, but I’m gonna be honest; those two sentences betray significant flaws in your understanding of the topic.

1. Energy efficiency and maximum luminous output are linked by the laws of thermodynamics. Efficiency and Efficacy are two separate variables, but again they are linked. To obtain the maximum possible light output, you must posses an LED with the maximum possible efficacy [approx 300lm/w], and then you must apply the maximum power possible to it (whilst keeping it’s efficacy constant by cooling it).
To even start talking about light output, you must first consider efficacy.

Relevant: http://m.phys.org/news/2010-08-white-super-high-luminous-efficacy.html

2. Direct current does not switch on and off, or vary in any oscillatory way. The word “Hertz” is to direct current what “quadrilateral” is to a circle. Absolutely unconnected.

But it helps everyone to discuss these things, so everyone can contribute positively to the discussion.

No need to apologize. As I stated. I am ignorant with poor communication skills.

Anyway we are veering away from where I was trying to keep this directed but I must let you know that you are both correct and incorrect.

I will cite two more references. The first of which more or less coincides with your response. The second is the one of real interest.

Now can we continue with the focal point?

When you see a picture, hover the mouse pointer over it.

If the mouse pointer changes to an icon of a little white glove with a pointing finger, or something like that
this means the picture is also a clickable link.

In the case of the chart I posted, when you click the link, it takes you to the full article describing that chart and much else.
That chart is “Figure 3” and the text next to it says:

So the red line that rises from left to right is the light output — numbers along the left side of the picture (lumens)
The black line that decreases from left to right is the efficiency (efficacy, lumens per watt)
The text under the bottom of the chart explains that’s the forward current in milliAmps, increasing from left to right.

i said ignorant not stupid hank. i read the article and followed up with a post.

we have gotten way left field on this. All I am trying to do is find a way to constantly maintain the peak output of an LED.

I will try to think of another way to express my thoughts. What I am trying to accomplish is not impossible.

But I have learned a lot from everyone. Thanks

Ejected Filament wrote: I could be wrong, or half wrong but Im unlikely to be completely right. <<<<<< I love it

Well, that’s the easy part… just give it a constant stream of peak power… and some extreme cooling. :smiley:

You say the second link is of real interest. It is not.
Perhaps you should read the first comment on that link.

_ “Very clever, but that’s not how it works.

By your reasoning you should not only be able to make the frequency infinite, but also 4 Hz, or 100 Hz, or 2√

Hz, all at the same time, with the same signal. And that’s why you can’t do that: a repeating signal can have only 1 fundamental frequency, which is 1/period.

It would be the same as taking 2 periods of the 4 Hz sine and saying that that’s the period, because it also repeats, and then the signal would be 2 Hz. It can’t be 2 Hz and 4 Hz at the same time” _

Continue based on false and impossible concepts?
Because that is the only way to continue here.
You should go back and read every post in this thread,
trying to understand them rather than trying to refute them.

> Quote: I don’t what the red line is representing? or the dashed line.

Remember — online, we’re writing for an audience, and some readers won’t get here for days or weeks or months in the future

When one person doesn’t understand, likely others coming along later may also not understand. So it’s, I hope, worth explaining even though YOU got it quickly.

You’ll see — from me and others — explanations you may feel insult your intelligence. They’re not for you.

Being brighter than average, you may be offended by explanations intended for younger or new readers.

Sorry it bothered you. It wasn’t about you.

The average reading level of US citizens for nontechnical subjects is 7th grade — lower for anything technical.
So we try to explain things in ways people can follow even if they’re having a hard time.

1. Acquire array of high-efficacy LEDs (eg. 10 XHP70s)
2. Directly thermally bond them to a nitrogen-cooled, copper, convective heat exchanger. (Eg. big copper cold plate with liquid nitrogen circulating through it)
3. Power them with a high-current, low resistance power supply (eg. a big bank of LiPo batteries)
4. Use a gold-coated parabolic reflector to collect all of the light, and direct it outwards in a certain direction.

Then you will have the maximum possible light output.

…Not very portable though. :smiley:

Angler - I agree. Any result of this discussion can only be based on assumptions and premises established at the beginning of the discussion, and information included during. While the discussed information is interesting and valuable in other contexts, it is not truly pertinent to the discussion, because the basis of the discussion is flawed.
One cannot accurately answer a broken question.

Hank - good point well said.

Dehc111 - earlier, you said the following: “All I am trying to do is find a way to constantly maintain the peak output of an LED.
I will try to think of another way to express my thoughts. What I am trying to accomplish is not impossible.”
I think that is quite a good summation of this discussion, but not for the reasons you might think. Obtaining the most light from an LED is very simple; feed a highly efficant LED lots of power, and keep it cool. That is not rocket science. You’re right in a way; what you’re trying to accomplish is possible - it already exists.
This discussion appears to be predicated on you trying to re-invent the wheel.

I was trolling….

Just kidding.

Hank - ^5

Again thanks to everyone who posted to this thread. Very informative.