M140 Test load

[niiii]

Hello, I need help with my DIY test load.. Im going to use this schematic

That Ive found in some another topic... I just dont know what diodes and resitor do I need to make it... I need to set the current at 1.8A for my m140 diode with SL-SD-3 driver.

 

[ARG]

Personally I would ditch the resistor and just use an ammeter.

For the diodes just use any regular si rectifier diode with a Vf of about 0.7V. Make sure they are rated for the current you'll be putting into them.

 

[niiii]

if im gonna ajdust driver 1.6 - 2.3A to 1.8A can I use diodes rated at 3A?

 

[ARG]

Yup, 3A diodes would work fine.

 

[niiii]

aaaand if I dont use the resistor it will look like the first schematic or the second in the picture

 

[grainde]

Try the first one....:tinfoil:

 

[ARG]

The top one, voltage is measured in parallel, current is measured in series.

Don't forget to stick your meter into amps mode.

 

[niiii]

thank you guys

 

[BShanahan14rulz]

make sure your meter is in amps mode, and that you use the 10A setting and the 10A banana sockets. Most meters will blow their fuse if you use the normal voltage sockets, as they are fused at ~250mA, while you'll be measuring current closer to 1800mA.

 

[niiii]

Ive found this diodes rated as 3A, but vf is about 1.2V... can I use them?
1N5408 DC COMPONENTS - Dióda: usmer?ovacia | TME Slovakia s.r.o. - Elektronické sú?iastky

 

[BShanahan14rulz]

It drops 1.2V when 3A flowing through it. It will drop less voltage if you are sending less current through it, you can probably assume 0.9V per diode at 1.8A.

 

[dregalado331]

Is it true that a zombie m140 would be a good test load I heard that even though the diode will only look like a dim led it still pulls the same current.

 

[marcuspeh]

Is it true that a zombie m140 would be a good test load I heard that even though the diode will only look like a dim led it still pulls the same current.

Zombie m140? Define it

Btw, the last post is more than half a year ago. Start a new thread instead of bring this thread up again

 

[dregalado331]

Zombie m140? Define it

I apologize for the terminology but I have failed once or twice on a build and the m140 would throw a good beam but because of overheating k or over feeding I killed the diode resulting in a glow but not a beam this has happened to not only the 140 but the lpc823 twin can and the 405nm diodes
They just glow but the current draw is the same ,,,,I was told they do get hot I suspect that the heat is the result of the current instead off the light so that is why they are zombie diodes because when they are good and really dead they don't light up at all

 

[123splat]

Yes, That IS a zombie. you are correct (to the best of my knowledge).

 

[dregalado331]

We ll I am not proud to say I have ac few zombies and if I don't improve my building techniques ill be on the next Walking Dead episode.