Results 1 to 9 of 9

Thread: Help powering up a Landwehr Q-Switch driver. Odd power readings. and.... KTP cooling!

  1. #1
    Join Date
    Sep 2012
    Posts
    64

    Laser Warning Help powering up a Landwehr Q-Switch driver. Odd power readings. and.... KTP cooling!

    Hello all, how is everyone? Good I hope. I have a small but major problem. I need either the data sheet or help with figuring the power wires for a Landwehr A251-14 Q-Switch driver. So it has a total of 5 power wires feeding it. 1-5v+, 2-5v-, 3-D-GND, 4-Case, and 5-GND. So I doubt this is powered by just 5 volts. Here are my DMM results. 5+ and 5- to case = +- 5v. 5v+ and 5- to D-GND = 5v+-. Here's where it gets weird. 5+ to GND = -18.5V. 5- to GND = -28.16v. GND to case = -24.1v. D-GND to GND = +24v. So I am at a lose as to how this thing should be wired. You may be asking how I have DMM results and asking to wire it. I have 2 systems. 1 is being converted to manual control and I ripped out all computer functionality so I now need to wire up essential things by hand. Any help would be greatly appreciated. Second problem, the system has a doubler unit consisting of 2, parallel KTP or LBO crystals. Im assuming they are set up for critical phase matching and paired for walk off compensation. When under stock control the system would bring the temp up to between 78-80degF. What I don't know is how it handles increase in optical output power. I was testing at 15% power. Each crystal has a TEC behind it. The TEC is cycled on and off with 3.5v, they are small. My question is during higher power operation should the temp be kept at that 78-80 deg or how should I handle it? Also I need a best guess at how much current I need to supply the TEC to maintain temp's. I had no way to measure current at the time and now the system control is gone so I cant answer and more questions that would require testing. Temp sensor is standard 10k thermistors. Each crystal is about 4x12mm best guess. I'm not to familiar with the critical phase matched regimen, most has been NCPM. Its also a guess that its critical based on temp, I cant say 100% that true, but it lases fine at that temp between a range of power between 1-12w's. Hopefully someone could help me out on this. The last thing I want to due id blow a Q-switch driver or a TEC that I cant really get to, to change out.
    Thank in advance to everyone,
    Adam

  2. #2
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,543

    Default

    See Gooch and Housego Deutschland for electronics help with former Landwehr. Start by contacting G&H Florida for info.

    Every dual crystal system I've worked on does not use active power compensation. You adjust the angle of the whole mount for peak green to compensate for adsorption heating. You are now in the realm of angle tuning. Do not think of the second crystal as just compensation, usually both are active doublers.

    Steve
    Last edited by mixedgas; 11-11-2014 at 07:24.
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  3. #3
    Join Date
    Sep 2012
    Posts
    64

    Default

    Good advise. Thank you. The angle is as good as I can get it right now, its within 10% of stock so I'm happy with that. Any idea why they would be heating it on start up to 80f and cooling it to keep it there during operation? It seems to go up at higher powers but still maintains the temp to about 100f. My main concern is the current I need to supply to the TEC's. All I know is the voltage, no idea how much current it would take to keep them cool. Any ideas or a rough estimate? IIm just very concerned with overdriving them.
    Thanks again.

  4. #4
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,543

    Default

    For various reasons I'm sure you'll understand, I'm afraid per policy I cannot help you any further with this topic.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  5. #5
    Join Date
    Sep 2012
    Posts
    64

    Default

    Steve,
    I am very confused. Either this is a mistake, or I need to address something with someone. I don't understand who would want you to stop working with me. If I have made an enemy somehow, someway (which I don't know how, I haven't posted enough to make enemies and im not on any other forum) I feel I deserve the right to defend myself and would ask you, or the person whom spoke to you, to contact me privately. If I didn't make an enemy, is it thread specific? When you say "sensitive nature" I assume you think its related to a very old post. However that system is gone, but I retain some parts, this being one of them. But it dosnt exist anymore, was broken down, parted out, on ebay as we speak, but I have made no mention of the system nor do I intend to. All I'm seeking is basic TEC info and Q-Switch specs, nothing earth shattering. If someone can help me in private that's fine with me. Am I banned from asking other questions??? I don't know where else to turn.

  6. #6
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,543

    Default

    I'm not placing data on such a high power green in public.
    You have made no enemies, your rights on the forum are not compromised.
    I was asked not to post the data when I looked into the hardware.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  7. #7
    Join Date
    Nov 2007
    Location
    SoCal / San Salvador / NY
    Posts
    4,018

    Question

    Quote Originally Posted by als1980 View Post
    ... I am very confused. ..
    I, too, am confucius... Why? Because all the past-times I've interfaced with user "als1980" / PM'd about either LS's, and / or HPS's, it has been a "Jane" (..I have a folderfull of PMs / comms with 'Jane'..) ..aaaand, now it's 'Adam'? I mean.. I'm not 'judging', here.. but.... Whence someone presents on PL, and - at first, is one name, then later another - asking about how to hot-rod 80+ Watt KTP / LBO / whatever, medi-lasers, well.. Let's just say that 'sketchy' + '80+ Watts of 532' won't usually = Help-on-demand, dig?

    ..So.. first off, are you Jane? Or, are you Adam? Or, are you Janadam? Or... are you neither creature?? Inquiring minds wanna know.. And, it's not to 'pry', or anything, but.. For all we know, you could really be, mmm, let's say an 'Allan', or.. (probably even-worse..) a 'Devin' for example.. Doesn't help the 'comfort zone' in helping with such-beasts, whether in public or private, sooo...

    ...in the immortal words of Roger Daltrey.... '(...Whoooooo ahU.. who-who, who-who...) ...Aaaah whoda *coff* ahUuu??'..
    Last edited by dsli_jon; 11-13-2014 at 14:51. Reason: link, singing
    ....and armed only with his trusty 21 Zorgawatt KTiOPO4...

  8. #8
    Join Date
    Sep 2012
    Posts
    64

    Default

    As to who i am i can clear this up eaisily. Jane and I are husband and wife who both share the same passion. If you want credentials on what lasers i have dealt with please look at "flutterby812411" on ebay. I can say with 100% certanty that i have dealt with as least some of you, either buying or selling including "Sam". I wasnt posting specifics because we had talked about not posting "things" openly. Thats why i put the model in there. If someone whos wheres its from then they are already deep into high power units. Its not run of the mill. My buying history pribly from some of you on ebay should show what kind of power levels i normally deal with, you will also notice have no interest in the "laser show" aspect of all this. So i do understand why you may have thought it fishy. I appologize for the confusion. Im just so pissed at the parts from this system i want to scream! Ive already had it functional, now im just trying to gain some fine control of the beam. There were rumors about canbus access which would make my life easier, but it seems to be vaporwear. I have long since ripped everything out and this project is way beyond hotrodding or having anybody even understand what its about. Dsli jon i will be PMing you. But i dont feel this post exposes any potential threats.
    P.S. Jon, my wife bought me the system ahe talked to you about as a suprise present. It came from DNAequipment.
    Thank you,
    Adam

  9. #9
    Join Date
    Nov 2007
    Location
    SoCal / San Salvador / NY
    Posts
    4,018

    Thumbs up

    Quote Originally Posted by als1980 View Post
    As to who i am i can clear this up eaisily. Jane and I are husband and wife who both share the same passion.
    Wow, that's rare! Congrats to both of ya's.. Lase-On, Kats!

    Quote Originally Posted by als1980 View Post
    P.S. ...my wife bought me the system ahe talked to you about as a suprise present...
    Double-Wow!.. That's one rad-Wife ya got there...It's truly not every-guy who's wife up and buys him an HPS!

    ..well, anyhoo, sorry of-no-help on the 'Landrover' or whatever it is.. Might check with PL-member 'Junktronix' - Kevin oft has 'odd OEM parts' going thru his shop, and is quite astute on the tech-side, so.. Might be worth checkin with him to see if he's had any 'bench-time' with yer lil chochkie, there.. Dunno, just an idea..

    ciao..
    j
    ....and armed only with his trusty 21 Zorgawatt KTiOPO4...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •