My cat Kiwi absolutely loves chasing laser pointer beams. The only problem is that the tiny little watch batteries in the pointers run down and dim after only a few minutes. I decided to build a better pointer.
I started by taking apart the laser pointer, where I found that it was powered by three little watch cells with a nominal voltage of 4.5v. After taking a quick look at the circuitry, it was pretty clear that the the diode was actually just a 5v part being under-driven slightly. I the laser up to a 5v bench supply for a few hours to make sure that nothing overheated and it was fine. To provide a nice stable 5v to the laser, I used a 9v battery connected to a 5 volt regulator in a TO220 package.
The larger battery required a larger case, so I chose the most natural format for a laser… a pistol! I went to one of the local big chain discount stores expecting to find dozens of toy guns with convenient battery compartments to choose from. Unfortunately, I was sadly disappointed… I guess gun toys are a lot less tolerated/popular/PC these days compared to when I was growing up. Determined to not leave empty handed, I settled on an assortment of 5 water guns for $5.
Anyway, I cut up the water gun a bit, mounted a switch behind the water gun’s original trigger, and secured the laser at the tip. The results are a laser pointer which will last virtually forever before having to change batteries mounted in a way cooler container! And Kiwi thinks that it is just great.
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