What does "insta-flash" mean?
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Bushman5
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when a bulb has too much power running thru it and it goes POOF (burns out in a bright white POOF)
Nitro
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TigerhawkT3
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This looks like a job for... The Welcome Mat!
Q: What is "instaflash"?
A: Since an incan bulb is whiter, brighter, and more power-efficient when it is overdriven, it is common practice to push bulbs almost to their bursting point. If a particular flashlight drives its bulb right at the edge, it may sometimes provide too much voltage and current (when the battery is fresh, for example), which will cause the bulb to burn out.
Overdriving LEDs causes overheating to various extents.
Q: What's the deal with LEDs and heat?
A: Forget anything you learned about LEDs from the National Geographic Channel's "Manmade" show focusing on flashlights, especially from the interview with the Philips employee. LEDs are quite efficient relative to other light sources, but they do produce heat. In fact, most aren't even 30% efficient! This means that the more power you pump through them, the more light and heat they will produce. Unlike incandescent bulbs, however, LEDs are actually damaged by heat. It's common for a well-driven power LED to exceed 120F (quite hot to the touch). Too much heat for prolonged periods can decrease the life of an LED or even kill it. The efficiency (and therefore output) of an LED suffers with heat as well, meaning that with most lights, there is a certain drive level above which the increased heat will actually result in less output than a more moderate drive level. To combat this, well-designed flashlights provide a method to get the heat away from their LED. The most basic (and by far the most common) method is the heatsink. This is nothing but a chunk of metal that contacts the LED and is heated by it, leeching the damaging heat away from it. The next step is to somehow transfer that heat to the environment, where it can dissipate. This means that the heat must have a "thermal path" which leads from the LED to the heatsink to the surrounding flashlight to the environment. Some flashlights benefit from being held by someone's hand so that their bloodstream can act as a heat pump (the blood near the flashlight is heated, moves away, and cools, and the cycle continues). Other lights have fins that increase the surface area which contacts the outside air. LED dive lights don't have much of a problem here, since the surrounding water is like an enormous heatsink. Bike lights benefit from the cool night air rushing past them.
Q: What is "instaflash"?
A: Since an incan bulb is whiter, brighter, and more power-efficient when it is overdriven, it is common practice to push bulbs almost to their bursting point. If a particular flashlight drives its bulb right at the edge, it may sometimes provide too much voltage and current (when the battery is fresh, for example), which will cause the bulb to burn out.
Overdriving LEDs causes overheating to various extents.
Q: What's the deal with LEDs and heat?
A: Forget anything you learned about LEDs from the National Geographic Channel's "Manmade" show focusing on flashlights, especially from the interview with the Philips employee. LEDs are quite efficient relative to other light sources, but they do produce heat. In fact, most aren't even 30% efficient! This means that the more power you pump through them, the more light and heat they will produce. Unlike incandescent bulbs, however, LEDs are actually damaged by heat. It's common for a well-driven power LED to exceed 120F (quite hot to the touch). Too much heat for prolonged periods can decrease the life of an LED or even kill it. The efficiency (and therefore output) of an LED suffers with heat as well, meaning that with most lights, there is a certain drive level above which the increased heat will actually result in less output than a more moderate drive level. To combat this, well-designed flashlights provide a method to get the heat away from their LED. The most basic (and by far the most common) method is the heatsink. This is nothing but a chunk of metal that contacts the LED and is heated by it, leeching the damaging heat away from it. The next step is to somehow transfer that heat to the environment, where it can dissipate. This means that the heat must have a "thermal path" which leads from the LED to the heatsink to the surrounding flashlight to the environment. Some flashlights benefit from being held by someone's hand so that their bloodstream can act as a heat pump (the blood near the flashlight is heated, moves away, and cools, and the cycle continues). Other lights have fins that increase the surface area which contacts the outside air. LED dive lights don't have much of a problem here, since the surrounding water is like an enormous heatsink. Bike lights benefit from the cool night air rushing past them.
Bushman5
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^ so technically, i could cool a LED down with dry ice (ie: put the heatsink in a dry ice tub) and then overdrive the hell outta it?
What everyone else said, except it really only refers to incan bulbs, because we like to push them up to the very limits of the bulb burning out to get brightest output.
The term is mostly related to the higher initial startup spike surge of current when switch is turned on. That initial higher "spike" of current happens in milliseconds, and if above the filament's melting point, the bulb will burn out...hence the term "instant" flash (shortened to instaflash). However, there is never a flash like a flashbulb. It just dies with no fanfare.
This is also why we are interested in various "soft start" devices such as resistor, "NTC's," Hotdriver, or AW's new driver to block (or reduce) that high current spike on startup that is required to initially heat up the bulb filament, after which a steady state, lower current maintains the filament glowing.
The term is mostly related to the higher initial startup spike surge of current when switch is turned on. That initial higher "spike" of current happens in milliseconds, and if above the filament's melting point, the bulb will burn out...hence the term "instant" flash (shortened to instaflash). However, there is never a flash like a flashbulb. It just dies with no fanfare.
This is also why we are interested in various "soft start" devices such as resistor, "NTC's," Hotdriver, or AW's new driver to block (or reduce) that high current spike on startup that is required to initially heat up the bulb filament, after which a steady state, lower current maintains the filament glowing.
NA8
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Freeze spray is supposed to work well for playing.
But this sort of thing is what you want to cool a LED for higher currents,
http://www.malkoffdevices.com/shop/index.php?main_page=product_info&products_id=15
Last edited:
Ron Schroeder
Enlightened
Yes, but how long depends on the thermal mass of the LED. The maximum current pulse rating of LEDs is at fractions of a second pulses.
The absolute max current you can push to the LED in a perfectly heatsinked (or massively so) situation is limited by the bond wire(s) connecting the actual LED die (the chip itself) to the package it's mounted in. Even an actively cooled LED can pop if you exceed the current capacity of its hair-thin bond wires.
oO
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