flickering 445nm

[denton808]

i typed in 445nm flicker/flickering in search box and came up with nothing. am i to assume others haven't had this issue? well im running my 445 a130 at 850 ma in jay robs normal aluminum host. (waiting on an order for his extended copper one).

well i do have long duty cycles, but only until the front feels a little warm. it started flickering recently. XD now it flickers and dims a little. i got a feeling i pushed it too hard. i'm gonna see how jay robs host fairs with the copper heat sink.

i used up 2 18650 batteries so far using a microflex driver, that's a rough idea of time.

 

[Prototype]

Is it flickering immediately or after being on for a while? If it takes a while, it's the driver's thermal protection kicking in, it's a rather neat effect to watch when you're graphing the power of the laser, though it's crappy when you're trying to use it.

 

[denton808]

oh it takes about a min or so to kick in. right when the barrel starts to get warm. hmmm... could that be because i'm using a microflex at 850ms? u think the microboost (w/e that other one was called) would work better?

 

[Prototype]

I'm not certain about the drivers, but if it takes a minute or so to start, then yes it's the thermal overload protection on the driver kicking in. I'd give some time to cool down when it gets there.

 

[laserboystuart]

For my 445 i have an 18650 kit with the longer copper heatsink with a microboost set at 900mA and mine flickers sometimes, but only when the batteries are low, try charging your batteries, see if that helps

stuart

 

[CrazyMonkey]

It is probably overheating, or dead battery.
This is a linear regulator right?
Does it have a heatsink?

 

[daguin]

Replace the battery and check all the connection (including the mechanical ones).

Peace,
dave

 

[nospin]

You need to sink the driver
my flex is maxed out and never flickers
but it did before I sinked it to the pill

 

[Kenom]

Is the output like this?

or is it like this?

If it's like the first, it is thermal protection on teh circuit or dying batteries.
The easiest way to determine if it's batteries though is if you let it cool down a minute then fire it back up, does it go back to it's normal behavior, because if it WERE the batteries, you would only get a second of usage before the battery voltage again dropped below usable range.
If it's like the second, then it's some faulty connection or the diode is dying.

 

[denton808]

it's more like the first. when i power it on it's nice and bright, but then after a while it flickers. if i wait for it to cool and i power it up it's fine, then it starts to flicker again. so yeah i think it's the whole thermal thing from what you guys are telling me.

how would one go about thermally heat sinking a driver? i mean obviously you can't heat sink it with copper or alluminum seeing as it'd connect the circuit. LOL.

glad to know i'm not the only one with this problem

 

[nospin]

Look at post #563

This is how I did it, it might give you ideas on how you can

http://laserpointerforums.com/f65/merged-445nm-pictures-video-thread-51335-23.html

 

[Kenom]

that's not entirely true. You CAN heatsink the driver, you just have to make sure it is on the component that is heating up and it's not connecting to the other components or the side of the host (if your using it for gnd or pos connection) I presently am using a groove2 and that is what is making that nice up/down plot that you see. when it gets hot it turns itself off to cool which only takes 1 second, then it's low enough to turn it back on which lasts for only one second till it gets too hot again and turns off again. a small ram heatsink cut down will fit perfectly on that chip and heatsink it very well.

 

[denton808]

ok i'll try look for some ram heat sink. is there a special glue or tape that is a good thermal conductor, but won't do anything towards my electrical things?

 

[nospin]

I doubt enough for over 1.5 watts
My sink is huge

 

[Kenom]

I use a special blend of epoxy and thermal compound to make a thermal epoxy.

 

[nospin]

silicone thermal compound?