Laser pointer modding - any tips? **Added pics**

[PalmettoTiger]

My Halloween costume this year includes 2 laser pointers. ("Shark With Frikkin' Laser Beams On Its Head.") Does anyone have any experience rewiring them to extend the switch off the body of the pointer? Basically, these are momentary switches like every other laser pointer, and I don't want to have to reach up and squeeze my costume to activate them.

I'm hoping that it'll be simple to solder some wire to the pointers, run the wire down my sleeve into a switch I can carry in my hand. I don't have the pointers yet, so I figured while I'm waiting I'd ask you guys to see if anyone else has done something like this.

 

[EULA]

depending on your budget, you could simply buy two trigger lasers for a rifle/pistol. Some have a removable switch with a wire that you could simply extend to your desire.

 

[PalmettoTiger]

Already bought the lasers, unfortunately. Wish I'd asked you first though!

<rationalization>The sighting lasers are probably too expensive and/or not beam-visible anyway.</rationalization>

Ahh, I feel much better after that.

 

[MichaelD]

Small, focused mirror in front of the lens will focus the beam much more tightly. BTW; substituting a 6v lantern battery (the big battery w/the spring-looking terminals on top) for the little button batteries it came with will produce a much more satisfying laser beam.

NOTE:

NOT respsonsible for accidental blindness caused by YOU due to you modifying your laser pointer to coincide with tips received in this thread.

 

[PalmettoTiger]

NOT respsonsible for accidental blindness caused by YOU due to you modifying your laser pointer to coincide with tips received in this thread.

Damn you, I had the lawsuit half-drafted already.

OK not really; I'll have the lasers pointed straight up to avoid blinding people, and they'll be sewn into the costume so that people can't rip them off or change where they point.

I'm not too worried about the beam visibility, since I'm getting 20 mW lasers (FDA regs cap standard laser pointers at 5 mW) and the party's going to be at a smoky, dark bar. However, if I manage to rig up a remote switch and still have time, I might take you up on the 6v battery idea just for shits and giggles.

 

awesome costume idea

make your own battery pack, wire it to the contact points in the laers battery housing, have a switch wired into the wire

 

[sharkeeper]

Small, focused mirror in front of the lens will focus the beam much more tightly.

This will not reduce the divergence. VLD pointing devices for consumer use typically have a beam diameter at the point of egress of 2.5mm with a divergence of 1.25 milliradians. Reducing divergece requires a pair of convex lenses.

BTW; substituting a 6v lantern battery (the big battery w/the spring-looking terminals on top) for the little button batteries it came with will produce a much more satisfying laser beam.

VLD products are very sensitive to overdriving their inputs. Most likely, the laser diode will become a dark emitting diode! If the pcb has a potentiometer the current can be turned up to increase the output slightly. Exceeding 5.0 miilliwatts is in violation of FDA regulations!

As for the OP, you can easily modify by removing the small momentary switch and soldering wires to the pads on the pcb. Terminate these leads with a momentary switch you can hold in hand.

Cheers!

 

[dug777]

i never thought of General Hardware this way until now- next time my washing machine breaks down i'll be sure to come here for help

Great costume idea but!

 

Originally posted by: sharkeeper

Small, focused mirror in front of the lens will focus the beam much more tightly.

This will not reduce the divergence. VLD pointing devices for consumer use typically have a beam diameter at the point of egress of 2.5mm with a divergence of 1.25 milliradians. Reducing divergece requires a pair of convex lenses.

BTW; substituting a 6v lantern battery (the big battery w/the spring-looking terminals on top) for the little button batteries it came with will produce a much more satisfying laser beam.

VLD products are very sensitive to overdriving their inputs. Most likely, the laser diode will become a dark emitting diode! If the pcb has a potentiometer the current can be turned up to increase the output slightly. Exceeding 5.0 miilliwatts is in violation of FDA regulations!

As for the OP, you can easily modify by removing the small momentary switch and soldering wires to the pads on the pcb. Terminate these leads with a momentary switch you can hold in hand.

Cheers!

wow

it's also ironic that your username is "sharkeeper"

 

[PalmettoTiger]

HOLY CRAP. I just got the lasers and they are BRIGHT AS HELL. It hurts to look directly at the spot just shining on the walls of my cubicle. With the lights off - just indirect window light coming through - I can kind of see the beam, and that's with no dust. In a dimly lit bar with lots of smokers, I will be a veritable beacon of green lasery goodness.

For a test, I cannibalized a little bit of spare Cat5 (no one's going to need the brown/brown-white pair anyway) and secured one end of the wire to the inside wall of the battery compartment. I secured the other end of the wire to the battery's + terminal, clicked the button, and voila! Laser. Frikkin' bright, no less. Now all I need to do is buy a switch and splice it into the wire.

So, what kind of switch am I going to need? I'm reluctant to have both lasers on the same circuit; is there a switch where one lever or button closes two separate circuits without joining those circuits?

 

[sharkeeper]

Can you tell us more about the lasers?

They sound like DPSS (532nm) modules.

20mW of 532 is quite bright if you aren't familiar with them. I have some DPSS running upwards of 60W (60,000mW) but that is another story altogether.

Anyways, most small modules use (at 20mW) roughly 300-500 mA PER module at ~3VDC. The best switch type to use is a lever based micro-switch. They can be used simultaneously. The wires found in CAT5 cables will work, although there will be some voltage drop.

DPSS lasers are very sensitive to voltage drops. Fall out of the threshold of the 808nM pump diode and you will get absolutely no green even though you may have 100mA going in!

Cheers!

 

[PalmettoTiger]

Whew. Finished. Well actually, the lasers aren't mounted on the costume yet, but the costume is done - just waiting for the spray paint to dry. Also, I have the lasers rewired to a small hobby box, with an SPST momentary push-button switch for each laser. Both work, although one of them is tricksy - I can't decide if it's a really sensitive switch, or if I botched the soldering.

Sharkeeper, I looked all over the distributor's site but couldn't find any tech specs like you asked about. I appreciate you contributing your expertise, though!

I will definitely get pics tomorrow, as we're allowed to wear costumes to work. I don't know that the laser beams or points will be visible in the pics; that might have to wait until Sunday when I can upload any pics I take at parties this weekend.

Thanks everyone for your help and suggestions - without you this would not have turned out nearly as well.

 

[PalmettoTiger]

PICS:

Side view
Front view
Lights off, lasers on

If I get any good beam-visible pics this weekend, I'll include them too.

 

[imported_ultimus]

why laser? unless your halloween party is dark, inside a building (with ceiling to 'reflect' the light), it's kinda useless. no one can see the projection of the laser. better use big LED.

 

[PalmettoTiger]

A) because I'm obsessive-compulsive and if I'm gonna be a shark with friggin' laser beams, I will damn well have actual friggin' laser beams.

B) the green lasers are more easily visible than red lasers (due to natural tendencies of the human eyes), and these particular lasers are about 4x more powerful than the current FDA limit for laser pointers (technically they can't be sold as laser pointers). So, in a dim, smoky bar, I expect the beams to be pretty visible. In low-light conditions in my own house (lights off, but indirect light from windows on a cloudy day), I can easily see the beams.

What that says about the dust content in my house and my cleaning habits is a different thread altogether.

 

where'd you get those lasers

i want some!

 

[gsellis]

OMG! - I see a Fark Photoshop opportunity! :laugh:

 

[element]

if you want to see the beam in pics, and your camera has variable shutter, turn the lights off and use a slow shutter speed.

For example: this is a mere <5 mw laser pointer, and the beam is visible in the pics.

 

[PalmettoTiger]

I got mine from Wicked Lasers. You might be able to find a better source; I just went with Wicked because they were high on the Google search and had a Halloween special (50% off second laser). Google "OEM green laser" to find the ones rated above 5 mW.

 

[Slickone]

Originally posted by: PalmettoTiger
I got mine from Wicked Lasers. You might be able to find a better source; I just went with Wicked because they were high on the Google search and had a Halloween special (50% off second laser). Google "OEM green laser" to find the ones rated above 5 mW.

Dayum those are expensive. What do you people use these things for...besides halloween costumes?
My pointer was like $5, and easily hits the window of a house about .5mi away. <shrug>

 

[sharkeeper]

You cannot compare a green (DPSS) laser to a red (VLD) laser.

That is like comparing a bicycle to a harley, canoe to powerboat, etc.

Chris actually has good prices for turnkey products.

Cheers!

 

[element]

I can turn a key without a vesa local bus laser just fine. <shrug>

 

[tf8252]

I'm trying to disign a simple laser positioning system that would incorporate an audible alert signal such that when a laser beam is aligned with a recepter an audible beep tone is heard.

The recepter must be located on my digital camera (or a small bracket that will be attached to the camera), so the smaller the better (possibly a small mirror that could be adhered to camera?)

The laser source must be situated level on the ground and emit vertically, like this one:

http://www.electrical-contract..._StrLine_Laser_Acc.htm

Any ideas on receptor, switch, or parts to make this sort of thing?

Thanks in advance for your help

 

[sharkeeper]

I'm trying to disign a simple laser positioning system that would incorporate an audible alert signal such that when a laser beam is aligned with a recepter an audible beep tone is heard.

Over what distance?

If you're just looking for a simple on off ttl, this is simple. Any phototransistor can do it. You can go further by using a higher power laser in the 808 nM range. Two watt CW diodes (dangerous!) can be found in FC format on ebay for cheap. With proper handling (simple telescopy) you could have the range of 100's of kM but your gimbals better be perfect.

Cheers!