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ok...I gave it a shot. And I ran into the same problems again: I tried using a 5 ohm, 2 Watt resistor for the first circuit that you showed. When I measured the voltage across the resistor, the reading on my analog multimeter was 3 V. Now that means that the current from the AMC 7135 is...

I see. Then what explains my pot getting hotter as I reduced the resistance? I thought it made sense because the lower the resistance, the more current will pass through that resistor (instead of passing through the LD which was connected in parallel). So what I fear now is that my using a 5 ohm...

Ok....hang on for a sec: 1.) I am assuming this 'sense' resistor is the 5 ohm resistor that Paul put in his diagram. Now, I think the lower the resistance used, the more current will pass through it right? So I would need a 5 ohm resistor that is rated at 1 Watt or more right? I...

Hahahaha..... DMM = Digital Multi Meter.   Quite stupid of me not to notice that...heh. Perhaps its because I only have an analog multimeter. Hopefully that is adequate.   Hey Paul, let me get a couple of things straight:        1.) DO NOT place the multimeter leads and...

Paul, I really appreciate your effort man. Wow...I got quite a bit to test out before I can get this laser working. I wont be able to handle it now though, because I have just been called up for an exam (damn Med School). But I will give this a shot, and get back to you on it. Many...

I am measuring it after the 3 pots that have been connected in parallel. I am sorry but you have to tell me what you mean by DMM setting. Always 350mA? Are you saying that even if I put the resistors in parallel, the current will measure 350mA unless I plug the laser diode in...

Yes, as I mentioned in the last 2 posts, I did put the resistors in parallel. That's why I'm so perplexed. Initially, I wired one 100 ohm pot in parallel. Did not work, and the pot was starting to get hot. So I wired another 3 pots in parallel to help distribute the load. Still no result...

Hmmm...interesting. I thought that was the case too, so I wired 3 pots in parallel to help distribute the load. Still does not help. The current does not want to reduce (when measured with a multimeter), but can feel the pots getting warm a bit. Thanks for your help man.

Gazoo!!! I took your advise and purchased the AMC. It really small and great for my flashlight. But there is a problem: I wired it up but changed a couple of things: 1.) Instead of putting a 33 ohm resistor like you did, I put a 100 ohm pot. It is wired in parallel...

Whoops.... Did not realise that I was posting it in the wrong section. So sorry.

Gazoo, need your advice on the AMC7135. You mentioned that for the AMC7135, you have to connect the resistor in parallel in order to reduce the current flowing into the laser diode. That's confusing my calculations. Hmmm....so lets say for example: I need to put a 20 ohm resistor for...

Many thanks for the input fellas. I think I will wait for my AMCs to arrive before I start toying around with it. :-)

Wow....great link chido. Thanks. Yeah...it would be crazy to put a <5mw sticker on a much greater powered laser. Then hand it over to your lecturer to use it during his/her powerpoint presentation. Time to burn some holes on the projector screen. ;D :)

Cool man. Thanks a lot. :-)

Hey all, I have noticed that some of the DIY lasers that were built had those laser class stickers on them. You know....the "Warning. This is a Class 3B laser product .... etc". Just wondering, anyone got a good image file of that so that I can go print some coloured copies of it...

Hey fellas, Just wondering. I have received my new laser diode, but I don't have the regulators yet to start building a proper circuit. But I do want to test if the laser diode is functioning or not. I have tried hooking up a normal LED to a multimeter with the multimeter set...

Hey Gazoo, just realised something. The 7135 is a current regulator, whereas the 317 is a voltage regulator. Which should I be more concerned with? The voltage regulation for the diode, or the current regulation for the diode? :)

Hey Gazoo, Thanks a lot for your input. Really appreciate it. :-) Thanks for your help too Chido.

Ok Gazoo. I get you. Just two things that puzzles me: "Therefore the diode will be taking up the remaining 250ma's. The voltage going to the diode will be appx. 3 volts." 1.) But the datasheet says that you should be feeding 150mA and 2.5 Volts. Isnt this too much for the laser diode? 2.) How...

Hey Gazoo, This might be a silly question, but where in the world is the ground wire of the laser diode? Is it the same as the negative terminal? My AAA flashlight's negative terminal is connected to the body of the flashlight. So in this case, where am I going to plug the ground wire...