Quad 445

[carlos3621]

Anybody here, have any problems with running 445 diodes in series with the flexmod 3 ?
Im running a quad 445, withe a 24 volt 10 amp power supply, and cant seem to get the quad module past 2 watts...
What am i missing??

[dave]

without knife mirrors what is each diode doing power wise? What drive current do you have?

[dilbert]

Should be fine - exact same setup i used in quad - P3 & 24V running @ 1A.

[carlos3621]

Well, when setting up the drive current, out of the P3 driver,
Should the current read 1 amp , or 4 amps?

When i unplug the diodes, and read the current, with an ammeter,
And no load, right now its reading 1.2 amps....

Thx for the help!!

[dilbert]

In series is 1A to 1.2A so sounds like its working perfectly if thats what you get on ammeter / dummy load. That was max I ran mine at for no problems so I'd look at your lenses / mirrors/ knife edging to get the power from centre stripe etc Remove the mirror etc and measure just a single diode to see what its giving out.

[RGB LASER VERKOOP]

4 is serie need

voltage 6x4 = 24 ( so good)
and in serie there is only 1 current same treu all diode's

so it is correct.


some people advice me to use 7,5W for a driver of a bleu diode ( to make sure you get the start current / drempelspannng)
depending on the diode, so maybe.. (but i think not) you need a little bit more voltage...

but 1,2A is allready max load, so the power must be over 1W / diode or you blow them up allready.. then the power is verry low... but they keep working. i kill also some, now i keep them safe on 1A or less...

laser greets joost

[megaton]

Hi

Did you put any resistor in series?
Dumb question, but some did.

And whit 24 Volts is not enough if the resistor is like 1 Ohm.

Cheers,
Ed

[carlos3621]

Well, i need to brush up on my electronics!
Thanks for your help dudes..

[carlos3621]

Well, i picked off, one of the diode beams to check knife edge mirror loss, turns out there is 250mW loss, so there goes 1 watt !
Still missing another watt somewhere though...

Oh, another thing, there are no resistors used

[dave]

You will find a small amount of loss just from knife edging regardless of the mirrors due to loosing part of the beam with a tight knife edge

What mirrors are you using? I have some HR blue mirrors that are very low loss indeed