Make an LED Blaster

Step 5 Prepare the LED's

The LED's that I used for the main emitter are ridiculously bright, and their narrow viewing angle and large 10mm package makes them project really far. I used 3 of them clustered together and focused at the same spot. In order to fit them into the barrel of my blaster, I had to grind down the cases and crowd them together a bit.

The 2 sets of 10 blue LEDs that make up the chaser effect, (which I call the pulse generator) have their anodes connected to a common ground via individual current limiting resistors. Pairs of the cathodes (left and right side effects) are wired to the output pins of the 4017 chip.

Now, as bright as the big red LED's are, I wanted to be able to shoot a visible blast of red onto a wall across a well lit room, so I added a laser. I ordered a laser diode that included a focusable collimating lens. The lens allows you to change the focus of the beam so that rather that shooting out a little pin point laser, you can adjust it to whatever size spot you want. I made it about 10 inches across at 30ft.

Comments

[gctseng]

Why couldn't you have just used one resister per set of LEDs? It seems that there will only be one LED active at a time so it doesn't seem to be a problem of having the resister being overheated?