I don’t have much background in electronics but am very mechanically inclined and would rather build something myself then buy it.
I’m trying to make a laser training pistol to use with the LASR (Laser Activated Shot Reporter) software. Which uses a web cam pointed at a target on a wall to detect the light from the laser and show where the shot would hit the target on the computer screen. This a great way to practice without having to go to the gun range.
So my problem is that I want to control laser module (Wave length: 650nm. Output power: Class IIIa - less than 5mW. 2.6~5 VDC) using a momentary switch. But no matter how long the switch is held down it would only cause the laser to turn on for a fraction of a second, much like a flash on a camera but without the dimming of the light. Just on and off very quickly. My first thought was to come up with a circuit that uses a capacitor and when the momentary switch is open the capacitor is charged and when the switch is closed the capacitor would dump the charge and flash the laser once. But I don’t know how to make that circuit or what other components I would need.
The laser module would be fitted into the barrel of a real pistol and the rest of the electronics would be housed in the magazine well with the momentary switch placed right behind the trigger.
There is a pistol you can buy already but is way over priced. (SIRT Pistol $200)
My favorite chip the 555 was designed with your application in mind. The right one can supply up to 200ma on the pulsed output. Wear proper eye protection. Cost would be less than $5. Mention the duration you want the flash on time and someone here can tell you the proper value for the resistor and capacitor. Now that I think about it in your application you will want an extra resistor/capacitor combo on the “input pulse” trigger leads so holding the trigger down does not interfere with the output “On” duration. The relay and diode would be replaced with your laser diode and current limiting resistor. You want to use the drawing on the right.
AV-8B_Death_Pigeon:
… with the momentary switch placed right behind the trigger.
Why not fit a momentary switch into an empty case, where the primer would be. That way the firing pin activates the "shot", just as in real life ? Trigger control, if not recoil management, is still tested this way. This does rule out SA auto's but there's no reason you can't do it the above way for them. A Snap Cap might be easier to mod vs real brass.
To minimize wiring I’d try to put the 555 (or other) timing circuitry in the barrel w/the battery and laser too. Then I’d activate the timer via an IR light pulse, sent by the circuitry in the mod’ed “brass”. A revolver might get 6 pieces of mod’ed “brass” and 1 laser/timer bundle. Most auto’s would get 1 mod’ed “brass” and 1 laser/timer bundle. There would only 1 size laser/timer bundle and multiple calibers for the mod’ed “brass”.
IOW something like this, split into 2 functional and physical pieces.
Why not fit a momentary switch into an empty case, where the primer would be. That way the firing pin activates the “shot”, just as in real life ?
Mee_n_Mac
The problem with using the firing pin is that you would have to rack the slide each time the trigger was pulled in order to reset the sear. So instead of focusing on your sight picture and continuing to shoot you have to stop after each shot and rack the slide, then shoot again, then stop and so on and so on. At first I thought about getting something like that LaserLyte Laser ammo cartridge where it uses the firing pin to activate the laser but decided against it because of having to rack the slide each time.
oldtemecula
Thank you for the wiring diagram! The “flash on time” should be no more than two tenths of a second.
What is the formula used to figure out the “flash on time”?
AV-8B_Death_Pigeon:
The problem with using the firing pin is that you would have to rack the slide each time the trigger was pulled in order to reset the sear.
Understood, as said above for SA auto's (and Glock-like action) you'd have to do it per your OP. For DA/SA auto's and DAO's and revolvers you get the benefit mentioned. I have 2 1911's, the rest fall into the DA/SA category.
AV-8B_Death_Pigeon:
What is the formula used to figure out the “flash on time”?
See the wiki for more than you care to know. :mrgreen:
The trigger switch I think would be tricky to mount somewhere effectively. If you were my brother-in-law and lived down the street I might explore using an acoustic sensor on the gun (like guitar pickup) that triggers the 555 when it hears the dink sound of the trigger hitting.
The drawing I gave you is an idea but needs some adjustments for me to be happy if you get serious.
I could say more but you are going to have to marry my sister. (-‘
