questions concering my completed red

hello everyone.
I have recently gotten my first laser put together and is working beautifully
I haven't even asked any questions on here untill now.

currently the host I used has a switch on the ground of the circuit that is located in the but of the flashlight. this laser is working however what has concerned me today is I think I had a brainfart when I decided my wiring.
I am using the flexdrive v4 and is wired like this with 3 AAA batteries supplying 4.5 rated volts (measures about the same across the batteries) and this is how I have it currently wired.



well I awoke this morning and on my way to work I realized I could have wired it this way.



notice the changes with the ground.

now i have not seen the schematics for the flexdrive so I don't know would there be an electronic advantage that would be seen by rewiring the ground? I do know right now that I am bypassing the ground portion of the driver circuit.

as well. I had the driver preset to 180 mA I looked at the specs of the diode I have again. and it is saying 210 mA typical 230 mA max, with 2.5v typ 3.0v max.
now I did want to slightly underdrive the diode with hopes of it lasting longer. do I need a test circuit to adjust the pot on the driver or would I be safe taking readings across the diode and slightly tweaking the pot or is this a bad idea. and would I notice much of a difference in power by increasing it closer to the 210?

it is supposed to be a 200 mW diode and currently I am able to start smoking black tape about 4-6" away in about a second or two. I have been thus far unable to light a match (even with sharpy on it). any ideas on what the power of this red guy may be around?

sorry there are so many questions. as well I do understand that i am sure I could find most of these answers elsewhere and this site is a wonderfull resource. between this site and the rest of internet it got my laser working without any surprises.

thanks for the help everyone.

I believe the Lava drives are common ground. The addition of the extra ground is a good idea but likely not needed if the LD has a good solid ground.

DrLava sets those pretty close to requested current. Are you measuring the LD current in the + leg between the driver and LD?? With a 200 mW diode (there's many different ones), you should be getting about 100 to 150 mW at 180 mA drive. A 200 mW diode, if that's what it really is, should be OK at 230 mA with good heatsinking.
Where did you get the diode?

Mike

PS: Congrats on your first build -- welcome to the club of hands on builders.

I got the diode from ebay.
200mw laser diode 650nm Kip Kay project suitable - eBay (item 380147902826 end time Sep-09-09 09:29:07 PDT)

is the url to another auction he has.
or auction number 380147902826

would I be safe testing and tweaking the output with the diode on there as long as the joints are good? or do I risk killing my diode.

as well would I put the red lead from my dmm on the positive side of the diode with the negative lead on the negative side of the diode. I am sure I look the info up. man it has been a long time since high school electronics. well about 11 years anyway lol

otherwise it seems I should be in good shape eh?
as well do you think I paid too much at $40.00 for that diode do you think I could have gotten a comparable one elsewhere for less?

thanks again, these forums are wonderfull.

1: Insufficient data to identify your LD is provided.
2: Congrats on using a driver --- that saved your diode. KipK is dangerous to diodes.
3: If you connected the DMM across the diode like you say, you shorted out the driver circuit. It's amazing that the Lava driver regulated so well!!! The DMM probes need to be connected : red probe to the + output of the driver and black probe to the + lead of the diode. THis makes a series circuit with the meter reading the series current flow.
4: If you make GOOD connections this way, you can carefully adjust the current. Not knowing the diode number, I can't say what is a safe setting. Personally, I go for the MAX !!! I have a bunch of dead diodes to prove that :-(
5: There will be more people on here later who will also have ideas to help you.
6: Pop a balloon --- use a green or black baloon with a red laser.

Mike

You can get excellent red diodes right here at LPF. Check the group buy section for LPC sleds, these contain a long open can diode that lots of us drive at 420mA or even more. You'd get a couple of these sleds for your $40.00, they also have some useful optics and a couple of NIB magnets in there. The LPC diode will light matches no problem.

SCH ---

There you go --- the info I said would come to you!! He's right but I don't do much with red anymore. Also Senkat has reds for a good price. Start low $ and learn as you go. If you kill that diode - welcome to the club.

OH--- what heatsink / module are you using?

Mike

If you get the sleds, there is lots of info here on extracting the diode without damaging it. Sleds are a good way of collecting interesting optics like dichros, PBS cubes, polarizers, gratings, and lenses. Congrats on your DIY laser success. Got any pics ???

cool thanks guys.

I haven't hooked up the DMM to it at all I kinda trusted the one that tuned the flex. I was going to make my own driver but I didn't want a big hassle on my first laser project. the next I am thinking blue and I will build my own driver for it.

I will see about getting some pics linked before long.

here are some pics.

Sch --

What part of the world are you located?

Mike

yeah red LOC diodes run for about $10 each now, and they are capable of more than that diode.....so yeah you did pay too much, next time check out modwerx.com, or hightechdealz.com

small town North Dakota

Welcome -- another small town midwest laserist. It gets lonsome here!!!

Mike

My mom grew up in an uber small town in ND. It's practically a ghost town now.

hmmm.. where at abouts ND I have alot of family in several small towns around here.

I will have to take a look at some of the other places here in the forums for diodes etc. as well I do have working in the computer industry alot of cd burners etc. not so many dvd burners and cdroms I am sure I could scavenge some diodes from (not being the most powerfull but give a person summin to play with without much investment.

any idea what your avg cd burner diode can handle? I am sure it varies quite a bit but I was thinking about putting a driver or two together to and start at like 5-10 ma and slowly move it up.
how do you generally test a diode for stability at a certain amount of power just let it run for awhile and if it keeps going it must be good or what?

If you get a fast CD burner, the IR diode will have a little power, not as much as an LOC red from a 20x DVD burner. This IR diode will cut tape slowly if you give it 100mA or so. IR is not a recommended laser type for beginners to experiment with. IR has all of the eye hazard issues of any other type of laser, but is invisible or nearly so. You can hurt yourself without realizing there is a problem until it's too late. You need IR goggles, and you will need a vidcam to properly view the emission and be able to collimate. It's a good idea to have an LPM as well, so you can graph the output power as you step up the current a few mA at a time. The diode could be mounted in an aixiz housing using acrylic or glass (for red) lens. This is a near IR diode, maybe 780nm or so, the emission will appear to be a dim dark red. Don't be fooled by the dimness, at enough current and with good focus this will burn. Just not as safe or as powerful as a red or bluray.

She grew up in Streeter ND. It's in Stutsman County. We went there in the spring and there was practically noone there. Our family went to their centennial celebration in 2005, the streets were packed with people. It was fun.

I would not recomend an IR build your first build even if you have the diode readily available to you.