Does anyone have info on this Temp probe for my laser ?? Photo included...

[dolftb]

Hi,

I have a feeling my green laser is not working correctly. It has some type of overheat protection from what I have read but I cant find info, specs and or where I could buy this.

The prob has 2 tiny copper color wires inside a red tube and the head is black smaller than the size of a match head. It can bee seen in the left of the photo.

Who can help please . Thanks in Advance. Wolfman29 has also been trying to help me in my other post.

:thanks:

 

[Bionic-Badger]

Is that a green laser? Maybe it's the feedback power for the IR diode, not a temperature sensor.

 

[lazeerer]

Is that a green laser? Maybe it's the feedback power for the IR diode, not a temperature sensor.

It appears to be the same type of Green module that comes in those fire dragon laser from Dino Direct.

I think this is the exact type of this module came out of:

400mW 532nm Adjust Focusing Green Laser Pointer Pen (1x26650)

 

[Cyparagon]

Hmm... photodiodes aren't black. It's probably a thermistor. What exactly are you trying to do? Bypass it? Replace it?

 

[dolftb]

It look exactly like this one

Firedragon-III 532nm 350mW Flashlight Style Elite Green Laser Pointer Kit (Certified Power Guaranteed)

I bypassed the probe/thermister but it makes no difference. Startup delay with flickering until amperage reaches around 1,4 on the tail cap then increases to 2.7 amps and very bright.

Boeard look olay. I wonder if its the mosfet/rectifier that is not stable or on the virge of going out.

 

[Cyparagon]

How did you bypass it exactly? I don't think you'll get away with something as simple as shorting the leads. They're often employed as part of a voltage divider. A change in temperature leads to a change in resistance which leads to a change in voltage from the voltage divider. If you just short it, you either tell the circuit "the laser is at absolute zero" or you tell it "The laser is about to go super-critical." You would be better off replacing it with a resistor that has the same value that the probe has at room temp.

That might not even be the problem. Maybe you should just replace the driver :undecided:

 

[Things]

If the laser is slowly fading out, I doubt the thermistor is the issue. I'd be thinking more along the lines of something on your driver is getting hot, and limiting current to try save itself, or your module itself is getting hot, knocking the optimal crystal operating temperature or diode wavelength out to the point of not lasing anymore.

 

[dolftb]

I should have been more explicit. I didnt bypass the thermister i infact removed it completly. I did measure the resistance at different temps and established that it is working. It lowers resistance as it gets hotter. So if I leave it out, the driver will "think" that it is cold. I agree changing resitor might be a good idea but I am not sure what the value must be. Interestingly while the lase starts up with no green light, the laser is still pulling for isnstance .7 amps. So where is the power going ? why the erratic flickering during the long startup (sometime is flickers and sometimes it wont) And could it be a faulty MOSFET , this one is seperate from the board and easy to replace. Thanks for your ideas!

 

[dolftb]

The laser is not slowly fading out, it is slowly fading in at startup and sometimes flickering before it reaches full 2/3's to full power . There it remains stable uintil turned off. After a 30 sec cooling periode, When turning back on again it starts all over again.

 

[Cyparagon]

My recommendation: replace the driver (if only temporarily) to see if it starts behaving. I really don't think current changing from 1.7-2.4A is normal.