Driving Phr-803T diode at 400ma

[spaceman_hux]

I recently bought 4 PHR-803T sleds from daedal and have one hooked up to a full range rkstr. yesterday i accidentally turned the pot all the way clockwise. I am new to this hobby so i may be wrong but does that mean the diode was being driven at 430ma because that what the drivers max ma output is. The weird thing is that the diode didn't die its still alive and lasing i have turned the pot down though.
I am running the driver off a 9v battery.

The brightness didn't increases heaps or anything it just stayed the same.

 

[spaceman_hux]

:-? i dont know what happened im just curious does anyone know
i dont have a freak diode because it didn't get more powerful with the more current.

 

[Switch]

Yea , it probably didn't get a lot more power at that current, but it is possible for it to survive for a short time like that.

 

[treb76]

i disagree... i made that mistake one time as well. When i slowly turned the current up, I was looking at the wrong notch in the pot and went all the way around. The hole it made in the black plastic appeared to be about twice as deep as the others run at 95-105mA. Mine still lased for quite some time til the + shorted to the - host accidentally :'(

 

[rkcstr]

If you were driving from a 9V battery, likely the battery limited the peak output to something less than 250mA or so because 9V batteries don't have a very large amount of current potential. It would have been different had you used a 9V power supply or other larger capacity batteries of adequate voltage.

 

[Glaserfan]

9V battery output current testing

My thoughts exactly.. which is why you didn't see a major output increase. A 9V battery is about the worst choice for a laser.. they are made for a current draw of ~50-70mA. I do have an 803T build @150mA powered by a 9V, which functions quite well, but the battery is dying within 10 minutes of runtime :-/.

Just now did some testing.. A BRAND NEW 9V, with my DMM set on DC10A, started at 1.1A then died down to ~150mA within 15-20 seconds. A few I have with ~8.5-9v(minor use), outputted an average of 180mA at first, then dropped to ~120mA within seconds.

This is proof positive that most likely, your diode did NOT receive the 400mA the driver would have otherwise fed it.

Now to find a new host/power supply for my 803T build.. 9v's suck :-[

 

[treb76]

either way it burned a hell of a lot better :

 

[spaceman_hux]

thanks guys a had an incing that it wasnt really getting that much current and it explains why i had to buy a new 9v battery.
i think ill go with glaserfan's idea and find a new battery/host