Thermal issues of CNI's 532

[Sandstorm]

I've got 4 units of 1W CNI 532nm MGL-H heads. I've been good (more or less) with them, despite poor modulation comparing with anything diode or DPSS non-china etc. Though winter starting here and I had a show outside yesterday at -10 C temperature... now here they gone pretty bad. They hardly output any light at all. If I make some 'heavily green' frames for them to show for some time, they seem to heat up to output normally, but once these frames end they cool down instantly and have no output once again. Thinking about all that I come to the conclusion that CNI drivers simply doesn't stabilize temperature when it comes to TEC warming... I'm going to check them with the home-made driver to confirm this after the weekend. If it's not the case, then those heads simply don't have TEC heating at all (which I tend to believe they have... they should have, shouldn't they?)

Did any of you had any similar issues?

[hakzaw1]

subbing to hear more about this- thats really cold!!
do you manually change polarity to make the TEC heat instead of cool??

dont the fans and HS fins fight against you?? new stuff to me.

good luck-hk

[drm916]

The H heads are known to have bad temp regulation. I am pretty sure they are cooled only and not heated.

[norty303]

Yep, I'm pretty sure there's some recent threads about the fact most Chinese drivers only cool. I think Viasho have a new OEM head with heat and cool but they're the exception rather than the rule

[Sandstorm]

Yep, chinese drivers are failing. They don't have an ability to reverse polarity on peltier under KTP. well, basically they don't reverse polarity on any of peltier, however 808 doesn't actually need heating, even with low (winter) temp. (or does it? now I'm wondering what's the temp drift of 808 and in what wavelength output is at, let's say, -20C..?)
I've switched driver to home-made one today with both polarity TEC driving and the problem is gone. Means there's no problem in head itself, only drivers are bad. So, if you have issues with cheap chinese DPSS on winter - TEC driver capabilities is the case

[drm916]

Yep, chinese drivers are failing. They don't have an ability to reverse polarity on peltier under KTP. well, basically they don't reverse polarity on any of peltier, however 808 doesn't actually need heating, even with low (winter) temp. (or does it? now I'm wondering what's the temp drift of 808 and in what wavelength output is at, let's say, -20C..?)
I've switched driver to home-made one today with both polarity TEC driving and the problem is gone. Means there's no problem in head itself, only drivers are bad. So, if you have issues with cheap chinese DPSS on winter - TEC driver capabilities is the case

I had this issue latelty too on some H head 532s. The manufacture switched them out for me. I am sure they will eventually have the same issue. I think the F driver is hot and cold, but I am not totally sure.

For those of you that are switching drivers.. can you provide any information on what you are doing? There are a lot of us H users out here. I would like to have a solution before I experience any issues.

[Sandstorm]

I had this issue latelty too on some H head 532s. The manufacture switched them out for me. I am sure they will eventually have the same issue. I think the F driver is hot and cold, but I am not totally sure.

For those of you that are switching drivers.. can you provide any information on what you are doing? There are a lot of us H users out here. I would like to have a solution before I experience any issues.

If they switched you the drivers and you're good now, then you won't have this particular issue. I mean, drivers either have the option to reverse polarity for peltiers or not, there's no case of smth in between. If you chill the DPSS head to -10C for instance, and you have no problems - your driver provides TEC heating. If you bump into situation when the head needs to work for 10-15s before it reaches it's nominal power (I mean, when you give modulation signal, not the first 15s when you turned the power on), then temperature is not stabilized from the bottom - TEC only works one way - cooling.

I'll be able to provide the details of our drivers. We simply reverse engineered one of the DPSS drivers made in Germany (Medialas I think, not sure now, some time have passed) and changed components which works better (or are easier to find). I could probably even manufacture some if there is a demand, however I'm completely out of time for the nearest month at the least.