1 reply to this topic

[Roehaen]

Hey everyone,

I've recently found a supplier for Violet LEDs with a wavelength supposedly of 410nm (415 is near impossible to find at 3mm for a cheap price), and can get 1500 of them for around $150 USD.

Each LED is 20mA forward current (10 probably actually converted into light) at 3.5 Volts. So thats 35 mW per LED output as light. Since each LED is 3mm, I can fit about 11-12 per cm^2 on a conventional prototype board, which gives me about 385-420mW per cm^2, possibly more since I cut the current in half to account for heat.

I am going to use 3 - 220 x 100 mm Prototype boards, each holding 800 LEDs (I'm thinking 500-600Violet,300-200 RED... any suggestions?), one for each side of my face, giving me a grand total of 2400 LEDs.

My question is this: will this high of energy density fry my face? Should I lower the brightness using a PWM if I am to attempt this?

Also, will 410nm wavelength kill p.Acnes as well as 415 does? If not, will this extra brightness be beneficial to help make up for it?

Also, should I be worried about any UVA/UVB light being emitted by these LEDs, or are LEDs usually pretty narrow-banded? Should I invest in UV filters if I am going to build this?


Thanks!

[sanjoseskin]

Hey everyone,

I've recently found a supplier for Violet LEDs with a wavelength supposedly of 410nm (415 is near impossible to find at 3mm for a cheap price), and can get 1500 of them for around $150 USD.

Each LED is 20mA forward current (10 probably actually converted into light) at 3.5 Volts. So thats 35 mW per LED output as light. Since each LED is 3mm, I can fit about 11-12 per cm^2 on a conventional prototype board, which gives me about 385-420mW per cm^2, possibly more since I cut the current in half to account for heat.

I am going to use 3 - 220 x 100 mm Prototype boards, each holding 800 LEDs (I'm thinking 500-600Violet,300-200 RED... any suggestions?), one for each side of my face, giving me a grand total of 2400 LEDs.

My question is this: will this high of energy density fry my face? Should I lower the brightness using a PWM if I am to attempt this?

Also, will 410nm wavelength kill p.Acnes as well as 415 does? If not, will this extra brightness be beneficial to help make up for it?

Also, should I be worried about any UVA/UVB light being emitted by these LEDs, or are LEDs usually pretty narrow-banded? Should I invest in UV filters if I am going to build this?


Thanks!

what if the wrong wavelenth helps the bacteria grow, you guys ever think about that?