what type of switch will normally be off/ open but when activated and held in the on/ closed position will then go back to the off/ open and rest when the switch is released? I am wanting a to make a light flash once with each press of the switch and not stay on and then i want it to reset when released so that when switched the process will start all over again. so picture a gun you pull the trigger and a bullet comes out and when you release the trigger it resets and is ready to fire with the next pull or trigger in fact this is exactly what i want to do but instead of bullets I want a laser to flash. there is a video of the part I would like to make at Min 4:00 & 7:45 youtube.com/watch?v=B0Yax6VeOF4 and this page you can see how small the switch is, how ever there is a bit more room if I had to make it a bit bigger. http://www.glockstore.com/training-resources/training-devices/laser-module-only-for-ar-15

  • \$\begingroup\$ A normally open pushbutton with only "ON operation"? You mean like these: si.farnell.com/webapp/wcs/stores/servlet/… \$\endgroup\$ – Golaž Oct 3 '15 at 16:41
  • 2
    \$\begingroup\$ A Momentary switch. \$\endgroup\$ – Passerby Oct 3 '15 at 20:30
  • \$\begingroup\$ @Passerby, hmm, what is it the rest of the time? :D \$\endgroup\$ – Wossname Jun 20 '18 at 12:45
  • \$\begingroup\$ @wossname a cat in a box \$\endgroup\$ – Passerby Jun 20 '18 at 13:57

That's just a normally-open momentary closed switch, available in either push-button or spring-return toggle flavors, and you'd use it to trigger something like a 555 timer in order to keep the light turned on for as long or as short as you liked.

Like this:

enter image description here

  • \$\begingroup\$ Thank you for the help and answer, I think is makes sense to me! I found a video of the exact thing I want to make but it cost $300 I know there is no where close to that in parts and labor. I can source the laser cartridge petty cheaply on amazon and the aluminium part will not be hard to make but the switch and 555 time are they small enough to fit in to the size package I need pleas see Video and at min 7:45 he shows the part and how it works. youtube.com/watch?v=B0Yax6VeOF4 THANKS a gain @EM Fields for the info above! – Aaron Virgo 8 mins ago \$\endgroup\$ – Aaron Virgo Oct 4 '15 at 3:09

It's called a normally open momentary switch. A common example is a pushbutton. Most pushbuttons are open until pressed.

These things are very common. Try the search term "pushbutton" on a site like Mouser.


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