Recommended current for PHR-803T ?

[ReNNo]

I have recently bought two PHRs and both died at about 100mA after few minutes of using.
I use LM317 driver and it works perfectly.
Current is stable and forward voltage is just fine.

Diodes were inside axiz cases and cooled by heatsink.
I have worried about duty cycle, and never left diode running more than 30 seconds.

Is it all bad luck or I'm doing something wrong?
I'm waiting for another PHR and I don't want another dead diode after few minutes.

What is recommended current?
Many people say that I should live it on 100-120mA but I'm afraid that next diode will die after 20-30 minutes of working.

 

[chipdouglas]

How are you checking that your current is set at 100ma?

 

[Asherz]

You should be using 4 14N001 diodes in series with a 1 ohm resistor on the end attatched to the driver as a test load, measure MV across the 1 ohm resistor and that should give the current.

You may know this already but if not it may be helpfull

 

[ReNNo]

I checked current both ways.
With 1 ohm resistor and normally with ampermeter.
Both ways shows similar current.

And off course, I always check current with dummy load several time before connecting diode.
4x 1n4001 isn't enough to get 4.5-5V of forward voltage as BR diode provides.
I have used 7 silicon diodes.
But it doesn't matter, current is always the same.

 

[Deleted member 8382]

it's really strange that TWO diodes die at 100mA. 120mA isstill considered a safe current >.>

 

[ReNNo]

Should I say again that it was only bad luck and set third PHR at 100mA, or even 110, 120mA?

 

[jayrob]

Most people run them at 125mA's for 110mW's (AixiZ acrylic) for a normal efficiency PHR...

Sometimes when people use the 'solder blob' method of removing the PCB mateiral, they can over heat the diode. (although if done properly, there is no problem) Maybe this is what is happening??
Jay

 

[ReNNo]

There are 2 layers, PCB and flat cable and it isn't easy to remove.

I don't use solder blob method when removing PCB.
I just heat solder on pins and pull PCB and flat cable.
But I have never hold iron on pin more that 2-3 seconds.

What is the best technique to remove PCB material from diode?

 

[Deleted member 8382]

There are 2 layers, PCB and flat cable and it isn't easy to remove.

I don't use solder blob method when removing PCB.
I just heat solder on pins and pull PCB and flat cable.
But I have never hold iron on pin more that 2-3 seconds.

What is the best technique to remove PCB material from diode?

But one moment, you directly drove them at 110mA and asumed the current killed them? then ofc that's the error, you are for sure doing something wrong and killing them before. try to put low current and see if they work to know if they are properly built, then increase it to whatever you need.

i repeat, 100mA should not kill nothing, its even low.

 

[ReNNo]

OK.
I'll set driver to 80mA and use it on this current for few days.

 

[jayrob]

There are 2 layers, PCB and flat cable and it isn't easy to remove.

I don't use solder blob method when removing PCB.
I just heat solder on pins and pull PCB and flat cable.
But I have never hold iron on pin more that 2-3 seconds.

What is the best technique to remove PCB material from diode?

I do believe that most people use a solder iron to remove the material. I know that if you load the tip with solder first, it will quickly melt the existing solder when you touch it on there.

My method is to clip the pins clean with some very fine tipped snips. This takes some getting used to, but I don't have to worry about any heat issues at all. This gives me peace of mind... especially if I'm working with a more expensive diode...
Jay

See here:
http://laserpointerforums.com/laser_pointer_forums_3/forum/showthread.php?t=37511

 

[Forgottenalarm]

i put it in the housing and solderd the wires on before i did anything then did a test of my driver before hooking it onto the diode. my lowest pot setting was around 38 to about 140ish. i run mine in a big heatshink with thermal compund no more then 1 minute on 2-3 minutes off. i have no problems to date. maybe your driver is hooked up wrong or its a bad few diodes. post a pic of the pcb top and bottom.

 

[Warske]

Any chance you have put a switch between the diode and the driver? Many people have done this, and it can kill the diode.

A loose connection there can do the same thing.

 

[bennycast]

if i use a Phr-803t with a flex or micro driver of 115mA what will be the batteries that i could use? can i use any type of battery or is there like a battery voltage limit?

whats the PCB?

 

[Deleted member 8382]

lithoum type are best, it depends a bit on the driver but avoid the 9V battery since it usually can't give more than 80mA

 

[ReNNo]

Any chance you have put a switch between the diode and the driver? Many people have done this, and it can kill the diode.

A loose connection there can do the same thing.

I usually solder capacitor directly to diode pins so I don't have to worry if any wire is broken.

I don't have very fine tipped snips, only way is to do it quickly with iron tip.