NDG7475 1W 520nm - Cutting Out??

[mikeyjames]

Hi all,
Probably another newbie question.

I'm putting together NDG7475 1W 520nm I got from DTR with X-Drive at 2.4A.

I've put out a survival S4 ghost with extended copper heat sink.

All seems okay, except that it cuts out completely after about 30 seconds. Turning it off and back on starts it up again.

Just wondering if this is likely the driver overheating? If so, is there anything I can do about it? I understand that it may be possible to place a small heat sink in the diver but not sure whether I am able to safely take apart the back part of the module without damaging something?

Alternatively, it's this just some built safety feature that it's pretty much just telling me what the duty cycle it's.

BTY - ambient temperature is about 25 degrees C (77 F)

Any info or tips appreciated.

Cheers

Muck

 

[djQUAN]

if it is overheating, it should probably blink. Seems to have something to do with your battery.

What battery are you using? Is it fully charged?

 

[mikeyjames]

if it is overheating, it should probably blink. Seems to have something to do with your battery.

What battery are you using? Is it fully charged?

Hi,

I'm using Panasonic NCR18650B

Cheers
Mick

 

[RYDorDIE278]

Have you checked battery voltage before use?, is the battery a protected battery? or is it unprotected like the batts you linked

 

[mikeyjames]

Have you checked battery voltage before use?, is the battery a protected battery? or is it unprotected like the batts you linked

Hi again,
Sorry, I linked to the wrong batteries. They are protected and fully charged - reading 4.2v

I just tried a couple of cheap 18650 batteries and exactly the same thing. After about 25 seconds it turns completely off. A quick flick off and an again and it will turn back on but the second the time to tuning off will be shorter.

Appreciate the help

Cheers
Mick

 

[Svenvbins]

Does it look like

https://www.youtube.com/watch?v=ym4DW_lH4Dk&index=5&list=UUA-tFStY1xPFSZJPPfqXJHQ

or

https://www.youtube.com/watch?v=5pcfCPr9QgQ&list=UUA-tFStY1xPFSZJPPfqXJHQ&index=8
?

That was my 520nm (granted, only 50mW) just before I killed it because i gave it too much current. The "It takes x seconds to turn off, then when I turn it on again it takes less seconds to turn off, it flickers too" sounds really familiar.

EDIT: Should read more closely. You don't have the blinking issue. Gonna leave the post up anyways just to be sure.

 

[ChaosLord]

Did you get the battery extention tube for the S4? I ask because you are using 18650s in a host that usually takes 16340/18350 batts. Just making sure your using 2 batteries.

 

[mikeyjames]

Does it look like

https://www.youtube.com/watch?v=ym4DW_lH4Dk&index=5&list=UUA-tFStY1xPFSZJPPfqXJHQ

or

https://www.youtube.com/watch?v=5pcfCPr9QgQ&list=UUA-tFStY1xPFSZJPPfqXJHQ&index=8
?

That was my 520nm (granted, only 50mW) just before I killed it because i gave it too much current. The "It takes x seconds to turn off, then when I turn it on again it takes less seconds to turn off, it flickers too" sounds really familiar.


EDIT: Should read more closely. You don't have the blinking issue. Gonna leave the post up anyways just to be sure.

Sorry, I probably did a bad job of explaining. There is no flickering or drop in power, it just turns 100% off. If I then use the tail cap switch to then turn the power off and back on, the laser will power up again to full power, but this time, the time to complete loss of beam is shorter; maybe only 10 seconds rather than 25 seconds.

Maybe I should read better too as I just noticed your edit

Anyway, appreciate the help.

 

[mikeyjames]

Did you get the battery extention tube for the S4? I ask because you are using 18650s in a host that usually takes 16340/18350 batts. Just making sure your using 2 batteries.

Yep, I have the extension tube. Should have mentioned that.

Thanks
Mick

 

[jeffreythe00]

Have you tried directly bypassing the tailcap? Ive had a lot of issues with lasers that draw high currents. It tutned out being the tailcap in most situations.

 

[mikeyjames]

Have you tried directly bypassing the tailcap? Ive had a lot of issues with lasers that draw high currents. It tutned out being the tailcap in most situations.

Thanks for the suggestion. Just tried it and still cuts out after 25-30 seconds.

Cheers

Mick

 

[jander6442]

Measure the current by touching the back of the last battery with one lead and the heatsink with the other, see what the readings are or how quickly the current drops. I'm betting the cells are not what they appear, either way I would not use that small of a unit to house that pricey diode in. I would have a whole lot more beef or drop that current to a safer level those diodes really put out some heat.

 

[mikeyjames]

Measure the current by touching the back of the last battery with one lead and the heatsink with the other, see what the readings are or how quickly the current drops. I'm betting the cells are not what they appear, either way I would not use that small of a unit to house that pricey diode in. I would have a whole lot more beef or drop that current to a safer level those diodes really put out some heat.

Hi,
I can't measure the current yet as my multimeter only goes to 700mA. A new one is on the way. I have tested the batteries with another build ( a 2W M462 diode) and they seem fine.

The thing I find strange is that there seems to be no drop in power or flickering, it just stops. Turn on and after 30 seconds it stops. Turn the power on and off quickly and then it will go back to full power but only take 5-10 seconds to stop the second time.

I have the extended copper heatsink and used Artic Silver. The heatsink isn't getting anywhere near as hot as the M462.

I'm wondering if the Driver is overheating? What are the differences in symptoms between a diode and driver overheating??

When I get my new multimeter I will report back on current.

Appreciate the help

Mick

 

[DTR]

The X-drive will just turn off when it overheats and go into about a 30 second hibernation before being able to be powered again but it should run at least 60-90 seconds depending on input voltage @ 2.4 and 90-120 seconds @ 1.8A not sure which option you went with. Either way 20-30 seconds is way to quick so it could be a battery issue or maybe there is a problem with the driver but I have not seen any that strangly overheat quickly. If you want you can shoot the unit to me and I will test it with my bench supply to rule out a battery issue and ensure it is doing the duty cycle it should. If not I can replace the driver for you. Also in that host this diode does produce a lot of heat so about 30 seconds on and 30 off would be a good duty cycle for the diode.:beer:

 

[mikeyjames]

The X-drive will just turn off when it overheats and go into about a 30 second hibernation before being able to be powered again but it should run at least 60-90 seconds depending on input voltage @ 2.4 and 90-120 seconds @ 1.8A not sure which option you went with. Either way 20-30 seconds is way to quick so it could be a battery issue or maybe there is a problem with the driver but I have not seen any that strangly overheat quickly. If you want you can shoot the unit to me and I will test it with my bench supply to rule out a battery issue and ensure it is doing the duty cycle it should. If not I can replace the driver for you. Also in that host this diode does produce a lot of heat so about 30 seconds on and 30 off would be a good duty cycle for the diode.:beer:

Hey Jordan,
The batteries are genuine Panasonic NRC18650B (protected). Using the same ones with the 2W M140 diode and driver you sent me and no issues. I’ve also tried it with some cheaper unprotected 18650s and with 2 x 18350s (both good quality XTARs and cheaper ones). All the same result.

I got around to testing the current:

It sits pretty stable at 1.8A for about 30 seconds and simply dies. There are no fluctuations at all.

Then, as long as power is quickly disconnected, it will start up again and sit quite stable at 1.8A and then die after 10-15 seconds.

Then the third time quite stable at 1.8A and dies after 5 seconds.

If I give it a good 90 seconds then I get the full 30 seconds again.


It doesn’t seem like the protection circuit as there is no 30-second time period before it will power back up, or is the wait period only valid as long as you maintain power to the circuit? So would me disconnecting power reset the protection circuit?

I’m sure I ordered the 2.4A version so not sure why it’s reading 1.8A. But not really fussed about that part anyway.

Let me know what you think the issue could be. Rather than send from Australia to USA for testing, happy to wait as long as you feel I’m not going to damage the diode. Then next time I order another diode maybe you can send along a driver too.

Cheers
Mick

 

[DTR]

Not sure I would have to look at it. The 2.4A @ 8.4V will draw around 1.8A since it is a buck driver. The 1.8A would draw around 1.5A @ 8.4V.