Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Phlatlight Red LED From the Casio Projector Burns Stuff!






There is a huge difference between how much power you can install in a host between LEDs and halogen/incandescent light.

Lightbulbs get rid of most of their heat the same way as they do of light: out of the front, as invisible IR radiation. This is easily 90% of the heat produced, and also the reason you can run a 500W halogen lamp without any heatsinking whatsoever, as long as its not enclosed.

The heat created by LEDs and lasers is at much lower temperature, and radiating that away doesn't work very well, which is why heatsinks are required.

Lets see about that big red led here: about 8 amps at roughly 4 volts, call it 30 watts for a round figure. That is as much as the average laptop computer uses, and believe me, those do not work very well under load without the fan running, despite they have a way bigger surface area than any flashlight.

So yes: it is cool! For 10 seconds tops :)
 
Benm said:
There is a huge difference between how much power you can install in a host between LEDs and halogen/incandescent light.

Lightbulbs get rid of most of their heat the same way as they do of light: out of the front, as invisible IR radiation. This is easily 90% of the heat produced, and also the reason you can run a 500W halogen lamp without any heatsinking whatsoever, as long as its not enclosed.

The heat created by LEDs and lasers is at much lower temperature, and radiating that away doesn't work very well, which is why heatsinks are required.

Lets see about that big red led here: about 8 amps at roughly 4 volts, call it 30 watts for a round figure. That is as much as the average laptop computer uses, and believe me, those do not work very well under load without the fan running, despite they have a way bigger surface area than any flashlight.

So yes: it is cool! For 10 seconds tops :)
Click to expand...



True, and a very valid point, but I was referring simply to powering it, heat is an entirely different beast to tackle.
 
LEDs emit only blue (or in this case red) light from the emitter, which means that the only energy dissipated by IR is blackbody radiation. Just making that clear :D
 
Last edited:
Benm said:
Lets see about that big red led here: about 8 amps at roughly 4 volts, call it 30 watts for a round figure. That is as much as the average laptop computer uses, and believe me, those do not work very well under load without the fan running, despite they have a way bigger surface area than any flashlight.
Click to expand...
:thinking: Sounds a little like your presuming a Phlatlight flashlight wouldn't have a fan?
I wouldn't even try it without a fan. A cpu heatsink like this (dia. cut down) might be worth a try but I would prefer a custom heatsink with more fins.
 
Last edited:
Alright, just to confirm..

I know that AMC1735 chips can be added to each other in parallel.. just like in the four- chip boards that DX sells. -----> DealExtreme: $16.58 AMC7135 1050mA Regulated Circuit Board for DIY Flashlights 10-Pack

Is there any reason why I couldn't use 7 of these boards in parallel to drive the emitter?

I can provide heatsinking if needed, but I don't think that will be an issue If I use the 3.3V rail on a high current ATX psu. The drivers won't have to dissipate more than 1V, and the PSU will be able to supply well over the 7.4 amps going through the 7 boards.

Any issues? Any reason why I might be a fire hazard beyond typical measures?
 
Holy $hit!!! I am kicking myself in the face for selling all 3 of thes I had. That would make a sick flashlight. If anyone feels up to building me one I would trade a 1 watt 445nn laser for one.
 
Meatball said:
Alright, just to confirm..

I know that AMC1735 chips can be added to each other in parallel.. just like in the four- chip boards that DX sells. -----> DealExtreme: $16.58 AMC7135 1050mA Regulated Circuit Board for DIY Flashlights 10-Pack

Is there any reason why I couldn't use 7 of these boards in parallel to drive the emitter?

I can provide heatsinking if needed, but I don't think that will be an issue If I use the 3.3V rail on a high current ATX psu. The drivers won't have to dissipate more than 1V, and the PSU will be able to supply well over the 7.4 amps going through the 7 boards.

Any issues? Any reason why I might be a fire hazard beyond typical measures?
Click to expand...

As long as the chips are heat-sunk and input voltage is close to output then you should be fine. I found that 2.8A from 8 in parallel on a small board was far too much heat to handle when run at 5V (down to 3.2-3.6 iirc), making it run closer to 1A. Don't these have a minimum voltage drop as well as a maximum though? They have a thermal limiter anyway, FYI, which drops the current if it detects temperatures are too high. That stops the driver from desoldering itself.
 
yobresal said:
Holy $hit!!! I am kicking myself in the face for selling all 3 of thes I had. That would make a sick flashlight. If anyone feels up to building me one I would trade a 1 watt 445nn laser for one.
Click to expand...
I asked if you could put this in a flashlight... everyone said it would have to be freakin HUGE...
 
Damn, thats some furious LED.
BTW, is there a green led in this projector as well? Havent seen any mention about anything green inside it. Besides its name.
 
There is a green phosphor wheel that produces the green light from some of the blue LD's.
 
brando132 said:
There is a green phosphor wheel that produces the green light from some of the blue LD's.
Click to expand...

Actually from all of the blue lasers - just "pulsed". For one cycle the red LED is on, for the second cycle the wheel is in the way of the blue beam, making green by fluorescence, and the final cycle the blue laser directly shines. In this way, all colours can be made efficiently, and if cycled fast enough (180hz) the colour "flicking" is not visible. The main issue with switching the colour rapidly like this is the "rainbow effect" (which really distracts me when watching video on a cheap projector).
 
To me it wouldn't be safe. It probably will draw excessive current until either the LED or PSU gives up. You could use a proper resistor, but it will limit you to 2A.
 
You must log in or register to reply here.


Back
Top