Can you break the LED flash by using N1 Torch?

[bbsydney]

I'm the developer of N1 Torch, and was pointed towards this thread. So I can offer some answers and insight...

Standard brightness is supported 'naturally' by the LED kernel driver. I tell it to come on, and it comes on until I give it a command to turn off.
High brightness is only enabled by the kernel for ~0.5 seconds before the kernel turns it off automatically. I simply send the command repeatedly to keep it on.

I had the app tested on a sacrificial N1, and the following were the results:

- On standard brightness mode, the torch ran for over 1/2hr continuously with no problems or heat issues detected.

- On high brightness mode, the torch was noticeably warm after 1/2hr, and there was a bit of a 'heat' smell coming from it. After a further 18 minutes (total 48 minutes) the LED started flickering of its own accord and was hot. After cooling, it resumed working normally (no idea how the lifetime was affected).

You can use your own judgement based on these results (and of course, YMMV due to manufacturing differences). I would be happy to say that standard brightness is fine for extended use (1/2hr at least), but try to limit high brightness to a few minutes at a time.

 

[djxs2000]

I wouldn't chance it

This company called idea softworks claims they won't even come near the LED backlight because they dont want to chance breaking people's phones

Hi,

I rooted my N1 and installed a flashlight app (N1 Torch) that uses the phone's LED flash. It warns you that continuously using the flash might break it, though.

What has been your experience? Does "continuous use" mean "hours", "minutes" or just "more than the 0.5 seconds the flash is supposed to turn on when you make a photo"?

 

[rori~]

I'm the developer of N1 Torch, and was pointed towards this thread. So I can offer some answers and insight...

Thanx for the statement*!

 

[ztm.000]

It's an LED.. by default LEDs are low-power, have low-heat emission and super long lifetimes. They also tolerate turning on/off repeatedly for extended periods of time.

I somehow doubt you could do any damage to the phone/LED.

true. you cant just simply "burn out" the bulb. think of led flashlights? led headlights. led's are supposed to last years

 

[bri3d]

true. you cant just simply "burn out" the bulb. think of led flashlights? led headlights. led's are supposed to last years

Temperature generally exponentially decreases an LED's brightness and life, so I wouldn't be using high intensity mode for more than a few minutes at once if it gets hot (not to mention the negative effects of heating the rest of the device, especially the nearby battery!). That's why really high-intensity LEDs that are designed to be used for long periods of time always have a large heatsink bonded to them. Higher current also increases the rate an LED degrades at, although the effect is nowhere near as significant as temperature. But, if it's higher current causing the higher temperatures, the effect stacks and LEDs can get degraded quite quickly. If you take a quick peek around online, manufacturers generally publish T50 (half-life) charts that indicate how quickly their LEDs will degrade at a given temperature.

On the other hand bbsydney's tests of normal intensity seem to indicate no noticeable heating, which suggests that any visible wear to the LED will occur years after the N1 is obsolete (and your battery is worn out).

However, as a word of caution, I don't think anyone's done any research into how the LED is driven - I suspect the driver is probably something specced to the task which is intelligent enough not to be easily damaged, but there's always the possibility that whatever is driving the LED is not designed to do so for long periods of time (i.e. they're just sinking it off an I/O pin on something, assuming it won't be used much). And obviously sinking more current is going to have an effect on the battery no matter what.

All in all, I wouldn't use high intensity mode for more than a few minutes, but unless we hear about someone's device becoming damaged from regular mode (which I think is incredibly unlikely) I feel very comfortable using regular brightness for as long as I want.

 

[stats101]

Erm.. the torch light application on my xperia x1 melted some component in the phone which stopped the vibration working - and mine wasn't the only one it happened to.

 

[khaytsus]

Erm.. the torch light application on my xperia x1 melted some component in the phone which stopped the vibration working - and mine wasn't the only one it happened to.

Seriously, don't resurrect old threads, they eat brains and cause problems.

 

[pakraider]

Seeing that Froyo natively lets you turn on the LED light for video recording, it's probably safe in moderate use (I wouldn't leave it on for half an hour at a time or something)

 

[abdulchik33]

Hello,
I hope some body can help me,
iam used N1 Torch more than 1/2 hour,and thin LED Flash Camera nor working more!!!!
it will be work after cooling?or not?
and what i can do?

 

[khaytsus]

Hello,
I hope some body can help me,
iam used N1 Torch more than 1/2 hour,and thin LED Flash Camera nor working more!!!!
it will be work after cooling?or not?
and what i can do?

You tell us; is it working now? I suspect not. Does N1 Torch have a "turbo" mode or something?

 

[clustered]

Hi all,

In the 1st place, I afraid it will burn my LED but after using it many times, it really does help me anywhere in dark! I dont face any problem while using N1 Torch...

In a party, I will use N1 Torch with strobe for more than 1/2 hour... Girls will be around for that strobing light.. Haha! Its awesome apps! N1 Torch had no any problem! My LED working fine till now! Special thanks goes the N1 Torch developer bbsydney. Thanks bbsydney!

 

[khaytsus]

Hi all,

In the 1st place, I afraid it will burn my LED but after using it many times, it really does help me anywhere in dark! I dont face any problem while using N1 Torch...

In a party, I will use N1 Torch with strobe for more than 1/2 hour... Girls will be around for that strobing light.. Haha! Its awesome apps! N1 Torch had no any problem! My LED working fine till now! Special thanks goes the N1 Torch developer bbsydney. Thanks bbsydney!

Outside of camera use, the LED on the N1 is useful for a midnight run to the bathroom or such.. If you need a flashlight, buy one.

 

[cicrockets]

On a side note: do any of the leds on y'alls phones turn noticeably blue after like 5 seconds on high brightness? Turning it off and back on fixes it for another 5-10 secs.

Can't exactly test it at this moment because High-intensity is broken on the newest nightly.

 

[khaytsus]

On a side note: do any of the leds on y'alls phones turn noticeably blue after like 5 seconds on high brightness? Turning it off and back on fixes it for another 5-10 secs.

Can't exactly test it at this moment because High-intensity is broken on the newest nightly.

Blue = bad.. It's being overdriven if it's blue. I use Tesla on my N1, and it appears to only have one brightness, although I haven't compared it to using the camcorder function light.. Anything that makes it brighter than that is a really bad idea for any length of time.

 

[zer0day]

What exactly is it N1 Torch does that can cause problems with the LED? I wrote my own flashlight app and use it for minutes at a time and haven't noticed any problems but now I'm starting to wonder if my app can cause my LED to burn out.

 

[vegetaleb]

With the N1 Torch app you have 2 levels, normal and extra bright.
Using the first one it's not very strong but it will work easily 1 minute before getting hot while the extra bright is very strong but heat fast,you can only use for 30 sec and let it cool down before using it again

 

[houzuoguo]

I limited my TelsaLED application to turn on the LED for 1 minute maximum.


Once I attempted to turn LED on for few minutes and the LED got hot , since then I only turn it on for 1 minute every time.

 

[xm0is3sx]

i left mine on for at least 10 mins and it never got hot im using teslaLED

 

[galaxys]

I've used the 'Nexus One LED Flashlight' widget for a few minutes and did not notice any heat. But I don't plan on leaving it on any longer...

 

[dogiedogie]

LEDs don't get that bright either, not the ones you are thinking of. The LED in the nexus one is much brighter than "usual", and it's also much smaller.


(bold for emphasis)

http://en.wikipedia.org/wiki/Led#High_power_LEDs

Obviously the LED in the N1 is designed to deal with its heat under "normal usage" for a camera flash, and it probably can handle longer usages than the stock camera, but I wouldn't push it too far.

Edit:
If anyone wants to use some debug tools to find how many mA the phone pulls when the flash is on vs when its off, they could probably look up the usual heat generation for an LED of that size and see how 'safe' it is to run.

Just using the power draw widget and noticing the difference, you can see the LED flash on 'normal' [not high] uses ~250ma