GBPPR MIL-SPEC Laser Dazzler |
Overview
The summer of 2011 saw a large amount of rioting and "flash mob" violence commited by non-Whites all over the world. This just might be the trigger needed to finally start waking people up...
In the mean time, you may need some non-lethal weapons to help protect yourself, your family, or your business, from these savage beasts.

This project is an improvement on the laser dazzler project from Issue #86. The goal of this laser dazzler is to make it a little more "MIL-SPEC." The physical ruggedness of the overall laser dazzler design will be improved, along with an increase of the laser output power to around 100 milliwatts. An optional 15 Hz laser pulse circuit will also be used to further increase the effectiveness of the laser dazzler.
The 100 mW / 532 nm green laser diode module used in this project is the same one which is often available on eBay by various sellers out of Baton Rouge, Louisiana. The laser diode module by itself isn't very rugged, with the main lens assembly being made from plastic and secured using a dab of glue, but for the low-cost (bidding usually starts at 1 cent and will go up to around $10), this laser diode module will work just fine.
The main body of the laser dazzler will be made from standard PVC pipe components and the laser diode module will be housed in a short piece of copper pipe. This design significantly increases the ruggedness of the laser dazzle and the small copper pipe section acts as a heatsink to help prolong the life of the laser diode.
The dazzler will be powered from two "AA" size batteries providing a total of +3 VDC. The current draw of the laser diode will be around 300 mA. Note that the brass body of the laser diode module will be at a positive voltage potential and may require additional isolation from any other circuitry.
The 15 Hz flasher circuit will made from a CMOS 555 timer and TIP42 PNP pass transistor, all of which will be housed in the PVC handle. 15 Hz was chosen as this is near the "seizure" frequency, but you may wish to experiment with other flashing frequencies. Note that when using the 555 timer for flashing circuits, adding a single diode across one of the timing resistors will give the output a 50% duty cycle.
Pictures & Construction Notes

Overview of the stock 100 milliwatt green laser diode module as purchased from eBay for around $10.

Removing the black plastic lens assembly.
There is a little bit of glue (that red stuff) on the threads which will need to be "broken" in order to adjust the lens assembly.

The stock lens focal setting provides a single point, like a regular laser pointer.
In order to user this laser diode module as a "dazzler," you'll need to expand the beam a bit.
Do this by carefully screwing the lens assembly all the way into the brass body.

To hold the laser diode module, we'll be using the front section from a 2-piece Andros N connector.
These Andros N connectors are available at most ham radio swapfests or from Tower Electronics (www.pl-259.com) in Green Bay, Wisconsin.

You'll need to drill out the center section and tines of the Andros connector with a 21/64-inch drill bit.
The rubber washer should also be removed.

Next, drill a #43 hole into one side of the thicker section of the Andros connector, as shown above.
Tap the hole for #4-40 thread. Carefully make a matching divot in the brass body of the laser diode module.
A #4 set screw will secure the laser diode module into the rear of the Andros connector.

The front-end of the laser dazzle will be made from a 3-inch long piece of 1-inch diameter copper pipe and two matching end caps.
Drill 5/8-inch diameter holes in each of the end caps.
A panel-mount double-female N connector will be used as the attachment point to hold the laser diode module in the Andros connector. It will also be an attachment point for any additional external lenses.
You'll need to drill (or burn out) the center conductor and insulator material of the panel-mount double-female N connector.

Attach the panel-mount double-female N connector to one of the copper pipe end caps.
Note the internals of the N connector have been removed.

On the other copper pipe end cap, drill a 1/8-inch hole all the way through (near the end) and through the matching 3-inch piece of copper pipe.
Solder an old panel-mount N jack to the end cap. This jack should also have its internal center conductor and insulator material removed.
This will be the attachment point to secure the copper pipe front-end to the PVC handle.

Internal view of the soldered panel-mount N jack.
Note the internals of the panel-mount N jack have been removed.
You'll need to use a propane torch in order to provide enough heat solder the N jack.

Attach the laser diode module connector to the panel-mount double-female N connector, as shown above.
You'll also want to solder two longer power wires to the laser diode module at this time. Teflon wire is recommended.
A dab of Loctite on the threads of the N connectors is also recommended.

Prepare and clean the the copper pipe sections with Copper Glo and a scrub pad.
An optional short piece of cardboard tube from a model rocket was slipped over the laser diode module driver board.

The front copper pipe end cap will be attached to the 3-inch long piece of copper pipe using some JACO Just-For-Copper solderless bonding glue.
Each section which the JACO Just-For-Copper is to be applied should be cleaned with emory cloth.

Completed laser diode module section.
The rear copper pipe end cap is held on using a long #4 bolt to make removal easier.

Optionally, to make an external beam expansion lens, use an old RG-8 compression male N connector to hold the lens between two neoprene O-rings.
Experiment with different lenses to get different beamwidths. You can salvage small lenses from some older video cameras.
A protective cap was made from the shell of an old PL-259 connector with tape over the open end.

Completed beam expansion lens mounted inside an old RG-8 male N connector.

To use the beam expansion lens, just screw it onto the matching N jack of the laser dazzler.
A plain piece of glass can also be used to make a optically-transparent protective cap for the laser dazzler.

If the lens requires an extended focal length, you can use long pieces of double SO-239 connectors when attaching the beam expansion lens.

To remove the center conductor and insulator material, heat them up using a propane torch and the internal center connector should just slide out.

Connect the double SO-239 connector to the laser dazzle with a cut down section from an old PL-259 connector shell.

Example of a lens which required a longer focal length attached to the laser dazzle.

Next is constructing the PVC body for the handle section of the laser dazzler.
You'll need one 1.25-inch diameter PVC cap (Genova 30159), one 5-inch long section of 1.25-inch diameter PVC pipe, one 1.25-inch diameter PVC female adapter (Genova 70314), and one 1.25-inch diameter PVC threaded plug MIP (Genova 31814).
A small piece of aluminum channel stock was cut for use as an optional switch guard.

The laser dazzle will be powered via two "AA" 1.5 volt batteries.
To secure the battery holder inside the PVC pipe handle, a couple of rubber grommets will be slid over a bolt which is then mounted inside the PVC pipe handle.
Note the threaded PVC plug was cut down a bit so it doesn't stick out so far.
A 1/4-inch hole should be drilled into the PVC pipe handle for the selector switch.

Drill a 5/8-inch hole in the center of the 1.25-inch diameter PVC cap.
Attach the cap to the laser diode section via the modified N connector and a matching nut, also salvaged from an old panel-mount N or SO-239 connector.

Overview of the laser diode flasher circuit.
A CMOS 555 timer pulses a TIP42 transistor at around 15 Hz, this in turn controls the +3 volts going to the laser diode module.
A center-off DPDT switch controls the "15 Hz," "CW," or "OFF" settings and main flasher circuit power.

Preparing the circuit board to be mounted in the PVC pipe handle.

The circuit board was slid inside a piece of heat-shrink tubing.
Note that the circuit board should not touch any metal parts on the front laser diode section which are at a positive voltage potential.

Internal handle view showing the rubber grommets on the bolt which the battery holder will press up against.

Completed laser dazzler.
Note that a 1-inch diameter copper pipe hanger mount was added to the front laser section to act as an additional heatsink and as a mounting point.

Laser dazzler beam (right) compared to a regular laser pointer (left) from around 10 feet.
Schematic
