Variable Laser Beam

[Zentron]

Variable Laser Beam?

I'll try to put forward what I mean as best I can, it's been a while, so please bear with me.

Basically, I want to make a laser beam that can be projected by pressing a switch/button as normal, but, with a second switch/button to change the duration of the beam into 3 settings.

First setting, push & hold the first switch/button for a steady stream of the laser light to stay on until you remove your finger of the switch/button, then by pressing the second switch/button, you change the laser to the second setting.

Second setting, press & hold the first switch/button for a single stream of the laser light to be projected for say, not longer than half a second, with no second stream to be projected until you remove your finger and press the switch/button again. Press the second switch/button to change the laser to the third and final setting.

Third setting, press & hold the first switch/button for the laser to be projected in short sharp rapid streams, again not for more than half a second, but continuing until to be projected until you remove your finger off the switch/button. Pressing the second switch/button to return it all to the first setting.

Plus lastly, with either an LCD or LED display showing '1, 2 or 3' depending on the setting that has been selected.

Not sure of the diffuiculty level, or if this is even possible for this, but it's just something that I want to do/try.

Just to mention, I stated in my intro post that I am a dyslexictedist, so the usual schematic diagrams are a little tricky for me to understand unless I have a visual representation of the object in question, say the battery symbol, I won't have a clue if it doesn't have a picture of a battery next to it, though it will all click eventually, it's just that it has been over 4 years since I last had to read and understand a schematic diagram

Lastly, I have just had to fork out a lot of cash getting my car back into shape, so I haven't got a lot to splash out on parts, at least until next months wages, though here is a list of what I have to hand at the moment:

Livewire PCB testing software (so whatever you can give me (if at all) I can up into that)
40x10 Strip Board
1.5A 250Vac 12.8mm Momentary Push Switch (red)
CL15R PCB Mounting Battery Box
7/0.2 Wire - blue, white, yellow, green
5mm LED red, green, yellow
2x 808nm CW 300mW Laser Diode (I know... but they were cheap)
2x 5.6mm 808nm Laser Diode House Housing with Lens (just found them)

 

[jbeng]

One problem you will have is that the 808nm laser diodes you have emit infrared wavelengths which are not visible. Additionally, 300mW of laser energy will do a number on your vision if it hits you in the eye. Doctors do retinal surgery with much less optical power than that. My advice? Get a low-power visible diode in the ~640nm wavelength range to experiment with. Most of all... BE CAREFUL!

 

[Zentron]

No worries, I have some IR safety glasses, plus, I'll be placing the laser housing in a special mount (which I will build), with the beam firmly aimed at a small matted carbon ceramic plate (I have a few pieces left from a old experiment), though I will buy a lower rated diode when I can.

 

[Zentron]

Right, well it seems I did not need to buy a new diode, I found an old laser toy with a 650nm 1mW diode in it and have just removed it... apart from short legs, it's A-OK to use

 

[Zentron]

Well I got myself a laser driver, the details are as so:

LM358 Constant Current Driver, 3.5 -5.0V - V2 2011

Constant Current Driver based on LM358 IC control.
Designed for 50-250mW red laser diodes and 50-300mW IR diodes (30-100mw green modules).
Standard 8.8 *19.5mm dimensions.
Specification
Type : Low drop-out linear regulator, precision current source
Applications: 808nm diodes 20 - 300mW, 650-660nm red diodes 20-200mW
Input Voltage: 3.0 – 5.5V
Output Current Range: 50-300mA
Dimensions: 9 x 20 mm

Now, whilst not picture perfect and for illustration purposes only (though does come close), these pics represent the design I have in mind for my experiment:

**broken link removed** **broken link removed** **broken link removed** **broken link removed** **broken link removed** **broken link removed**

And for those worried I'm going to burn my eyes out:

**broken link removed**

I found a circuit diagram online that I am going to try modify to suit what I wanted stated above, but I'm sure I'm gonna mess it up, so any suggestions will be very very welcome. (and anything else you believe I might need to buy/plunder)

 

[carbonzit]

I can't believe it; I may have come up with the control logic for this project. (Amazing because I'm far from an expert in this stuff!)

The following circuit might work:

**broken link removed**

OK, here's how it works. This is adapted from another sequential circuit I was working on, where a pushbutton cycles through 3 LEDs; the 3 flip-flops cycle a logic "high" around a loop, and the LEDs light accordingly, driven by pulses from S2. That's your "mode" switch.

The other part of the circuit gates the laser. Depending on what "mode" you're in (i.e., which flip-flop is high), one of three AND gates is used. The first has one side tied to the trigger switch (S1), so its output will go high as long as the switch is closed (when you're in mode 1). The second uses a one-shot to generate a pulse; the third uses a 555, probably set up as an astable multivibrator, to give you your train of pulses.

Hey, I think this thing just might work! Of course, there are two pieces of the puzzle missing. A couple of simple 555 circuits ought to do the trick.

(I've only sketched in the transistor to drive the laser; someone needs to flesh this out, choose component values, etc.)

(Hat tip to crutschow, who helped me with part of this circuit)

 

[Zentron]

Thanks for the diagram carbonzit... I have no clue what it says at the moment, though I'm sure it'll click once I translate it into visual components

 

[carbonzit]

Don't run out and get parts yet. Someone needs to reality-check this (plus fill in the missing blanks).

Another way to skin this cat, of course, would be to use a microprocessor (like a PIC). Far fewer components, but then you have programming to do.

 

[Zentron]

Don't run out and get parts yet. Someone needs to reality-check this (plus fill in the missing blanks).

No worries, I was thinking more along the lines of searching the web for pics, then mashing them together in a collage

Another way to skin this cat, of course, would be to use a microprocessor (like a PIC). Far fewer components, but then you have programming to do.

Never used a micro-processor before, so probably not the best thing for me to try