Make a "blinker" for LED panel?

[elizabeth]

Red LEDs/Skin Rejuvenation

Thanks for this, Steve. Yes, I agree it probably would not be a good idea to stare into the light and I have seen that eye protection is often used.

I found some more research that suggests a 630/850nm combination is most effective for my purposes. When using one wavelength, most sources say to use 660nm.

I like your 3 watt suggestion.

Elizabeth

 

[elizabeth]

Here is the article for the suggested wavelengths:

http://www.ncbi.nlm.nih.gov/pubmed/22804869?dopt=Citation


Here are some specs on a machine called the DPL. Can someone explain joules to me?

154 880nm infrared LEDs and 20 660nm red LEDs, engineered to produce 4 joules of energy per cm2 in 9 minutes or 8 joules in 17 minutes.

 

[elizabeth]

Joules delivered?

I found the following example on how to determine the joule delivery to skin. My brain hurts. Can anyone figure out what this means and how my grow panel compares? If, as you have guestimated, my panel has an output of 3mw/cm^2 and my surface is 900cm^2, by the figures below, 3mw/cm^2 divided by 4000
Can someone guess how many minutes it would take with my panel to deliver 4 Joules per cm^2???


Example:



A LED device has these specifications:



Red (wavelength 633 nm). Power output 8.4 mW/cm2. A mW is a milliWatt, or a thousandth of a Watt.



The light output is 8.4 mW per cm2 and your goal is 4 Joules per cm2 per treatment. One Joule is defined as one Watt per second, so in order to achieve that, you should know that J = W x S (Joule is Watt x Seconds)



In our case, we want to know how many seconds, so our equation becomes S = J / W. We just said 4 Joules is the target energy to be delivered to a square centimeter of skin, and the output of LED devices is stated in mW, so the formula to use is: Seconds of treatment per cm2 of skin = 4000 mJ / milliWatt per cm2 of skin.



4000 mJ divided by 8.4 = 476 seconds.



So each time you use the device, you should apply it for 476 seconds (8 minutes) on a skin surface area with the same size as the light emitting surface area as the device. This means that if you want to treat a skin area that is four times larger than the light emitting part of the LED device, that you need to move it over the skin for 4 x 8 = 32 minutes in total.



If the output per cm2 is not specified, look for the total output of the device and divide the total output by the total area of the panels with LEDs. This will give the Wattage per cm2. Example: Output area is 10 cm2, total Wattage is 50 mW. Wattage per cm2 is 50 divided by 10 = 5 mW.

The above was from: http://forums.owndoc.com/dermarolling-microneedling/led-skin-treatment/




Whew--Now, since 4 joules is the minimum "dose" and 126 joules is a clinical dose, I am wondering how one would ever make a device to reach a delivery of 126 joules in any reasonable amount of time?

 

[cjdelphi]

5% tolerance from a 60hz power supply...

Anyway how fast slow do you want it to blink? if it's slow then you might try a Solid State Relay (and control the mains voltage / on / off) ... but if it's a fast rate - more than 1 flash a second, it means opening it up and modifying it......

 

[elizabeth]

5% tolerance from a 60hz power supply...

Anyway how fast slow do you want it to blink? if it's slow then you might try a Solid State Relay (and control the mains voltage / on / off) ... but if it's a fast rate - more than 1 flash a second, it means opening it up and modifying it......

Hi--Well, originally, I just wanted it to blink and every 1 second would have sounded fine. Then I read some more and wondered if I could get it to blink at 200-300 flashes per.....Now, I am thinking it doesn't matter much if it blinks because it doesn't have enough power, anyway . Also--it won't open. We tried multiple tools and we would have had to break the thing to open it up. Thanks, though.

 

[elizabeth]

What I find odd about this treatment is that it's only used for a small number of seconds each day... But, when you look at other phototherapies, like for example 'biliblankets' they are used 24/7 to best achieve the desired results... It seems to me that if this red spectrum of light was so beneficial with such a short duration than a few hours (extended duration) of sun exposure each day would be of arguably of equal value...

I think I figured out why they use the biliblankets 24/7. It must have something to do with the joules of energy they can deliver. They probably can't make a powerful enough unit utilizing a blanket to have enough of an effect. Like my grow light. I think, now, that to get the same effect as I would by getting the treatment done with high tech doctor equip., I would have to hold the thing to my face for about 10.5 hours.

 

[elizabeth]

Oops--didn't realize when I posted that, that those blankets were made to deliver UV light to babies with jaundice. That's a whole different therapy.