output dropped on 16x gb diode

[jayhawker08]

I went to turn on my trusty dorcy mini laser that I built and the light didn't seem as bright. I focused it down and tried to burn some black paper and nothing happened. Now I know it's not dead because it is still quite bright (at least 3 to 4 times that of a 5mw). I check the current and it was pulling only about 65 to 70ma. When I put it together about 6 months ago it was around 150-180ma. Does anyone have any ideas why this might have occurred or if this is normal?

 

[MarioMaster]

your batteries could be dead or you somehow bumped a loose connection or changed the value of your variable resistor

 

[jayhawker08]

your batteries could be dead or you somehow bumped a loose connection or changed the value of your variable resistor

well I switched batteries and measured the output on both to make sure they were good and I don't have a pot, just 2 regular resistors in parallel :-? any other ideas?

 

[pseudolobster]

hmm... maybe if you were using eighth watt resistors one of them may have blown since you're probably running more than a quarter watt through the two of them, increasing the resistance since it's only going through one now, thus lowering the current?
just guessing... you may want to try measuring the resistance though.

 

[jayhawker08]

good thinking, but they are both 1 watt resistors. i measured the resistance and it is around 5 ohms, which is what it originally was. thanks for the suggestions, any other ideas? :-/

 

[Glaserfan]

Try measuring the drivers ouput voltage while the diode is running, if posible. If the output voltage has jumped way up, and consequently the current down, the diode is on its way out..

 

[jayhawker08]

I'm pretty busy for a while, but I'll try that as soon as I get a chance. thanks

 

[rog8811]

If the earth path is through the flashlight body try taking off the back cover, run a wire from the back of the battery to the front of the axiz module if that brightens it up you need to clean up your contact areas.....

Regards rog8811

 

[jayhawker08]

ok, I checked the voltage across the diode while it is running and got about 2.1 volts. I've never checked this before, but it seems kinda low. Am I right? btw, rog, I just read your post and may check that out soon.

 

[Glaserfan]

Low voltage.. opposite of my theory. Try Rog's idea, while you are at it check the supply voltage to the driver, if possible, with the batteries and switch in the configuration as you use the laser. If the supply voltage doesnt match the battery standalone voltage(+ supply wire disconnected from the driver), or drops WAY down under load, either it's what rog suggested, or a bettery problem.

You could also try a new battery connected straight to the driver via wires(no housing).

If none of these are to any avail, then the diode is bad unfortunately. Possibly the driver, but more likely the diode.

MOST diodes on their way out draw a higher voltage, though.

 

[toked323]

If its a Dorcy junior put a 1.2ohm resistor in series and it will give you about 250ma