Seimans LGR7631A Laser Pointer




Introduction: Seimans LGR7631A Laser Pointer

About: Jack passed away May 20, 2018 after a long battle with cancer. His Instructables site will be kept active and questions will be answered by our son-in-law, Terry Pilling. Most of Jack's instructables are tuto…

A while back a friend gave me this laser he found in a silicon valley surplus store. It sat around for a while before I decided to try to get it working. It is kind of beat up and looks like it had been sitting at the bottom of someone's junk box for a long time. The manufacturing date on the sticker on the tube says March 1987. After soldering a few broken connections I had it working with the pieces spread out on my desktop.

The driver board is mounted to the plywood with 4 #6x1 inch wood screws and 4 1/2 inch nylon spacers.

The transformer and the laser tube are each mounted with 2 #6x1/2 inch wood screws.

The laser tube is a Siemens LGR 7631A 1.5-2.5mW laser. (Not powerful enough to pop a balloon and not a lot more powerful than a little battery powered laser pointer.)

Do not point lasers at people, and I don't recommend them for cat toys, you might accidentally hit them in the eyes.

The laser can be found online, search for Siemens LGR 7631A.

Step 1: The Laser Tube

Shown lighted and unlighted.

Step 2: Connector

The wires from the driver board to the tube are very flexible fine stranded wire with thick insulation.

This is the polarized connector that connects the driver board to the laser tube.

Step 3: Transformer?

I am guessing a high voltage, high frequency transformer.

Connected with bayonet connectors, not polarized, I was careful to remember the polarity.

Step 4: Driver Board

The driver board and a closeup of the daughter board, which appears to be a filter and regulator.

Step 5: T-shirt

Just in case you are wondering, this is the image on the t-shirt that is partially covered in the intro picture.

Full Spectrum Laser Contest 2016

Participated in the
Full Spectrum Laser Contest 2016

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    6 years ago

    Interesting, but unfortunately, what we (in Mexico City right-now) need, is a powerful one to blind the murderous Ticket-cameras that our extremely greedy present day government has allowed the vendor to install in our city. The fact is that those greedy and perverse companies that promote (Bribe would be a more appropriate term) the government officials to install and impose those cameras, to get a ridiculously effective business model: They get 50% of the money from the fines, and the city officials get the other 50%. All good and fine, except that the damn cameras are calibrated to shoot at EXACTLY the speed limit... absolutely NO margin is allowed. That could be acceptable IF the local Major had not LOWERED the speed limits WAY TOO MUCH, which is affecting our transit times. That is only a part of a nefarious politic that pseudo-ecological governants are imposing on us right now; their agenda is to "DES-INCENTIVATE THE USE OF THE CAR"...

    Now look at this closely: It is NOT done in order to LOWER the emissions, or "preserve" the environment. It is done because the pseudo-leftist government has declared all motorists to be "enemies of the environment". Included are conterproductive and improvised measures like the NARROWING of existing streets by installing Bicycle lanes (used by very few cyclists), Exclusive TOO-Wide bus lanes that remain EMPTY and UNUSED more than 99.5% of the time (while the fewer remaining car lanes remain now badly congested for miles, emmiting MORE gasses than before!), imposing too-slow speed limits that augment overall emmisions by making the use of lower gears necessary, thus raising emmisions and lowering fuel economy and also wearing down the engines sooner. And there in no proof that some of those cameras are working "properly": several of them have been observed to take a photo of the licence plate at semaphore ligths, BUT a careful analysis of the cars being photographed has shown that even traveling just slightly slower that the posted speed limit, the time while the semaphore displays a yellow light is too short,INSUFFICIENT to complete the crossing before the camera flashes, and a ticket is issued!

    As far as my poor understanding of the USA Constitution's Second Ammendement, was meant to defend the citizens of this exac type of government abuses... please comment on this. Of course, a LASER powerful enough neesd to be handled responsibly and carefully. Amclaussen, Mexico City.


    Reply 6 years ago

    (Remember this is all hypothetical) You could use infrared LED's to drown out the license plate. They are as bright or brighter to cameras than normal LED's, but cannot be seen by human eyes. Just order a ton of bright IR LED's from China for a few dollars and wire them up. If one hypothetically wanted to destroy a camera, one might want to order a laser >2W (or 2000mw). That should do it; but the more watts the better. Hypothetically.


    6 years ago

    Solution to this is ridiculously simple, just really obey the traffic laws by driving a few kph under the posted speed limit. This cuts down, eliminates, speeding fines and causes massive traffic traffic congestion. After all, if everyone is paying strict attention to the law who can complain so fines cease, traffic snarls, traffic camera company loses massive amounts of money as does the city and mayor gets in extremely hot water over massive traffic snarls, everybody suffers for a few days but cameras go away as probably does the mayor (on a rail covered with tar and feathers no doubt) people rejoice and problem is solved with no blood being shed.