Infrared trigger circuit
ZakWolf, Tue Jun 17 2014, 07:22PMI have tried to browse the old forms and use the "google" but i have only been able to fine his
infact this is from my older project when i was first working with coil guns.The issue i found with this circuit is it is inaccurate and doesn't seem to trigger the SCR sometimes (although when it does work its fast enough t fire the second stage)
Is there a better one i can use or a modification i can make to this existing circuit
Re: Infrared trigger circuit
Skynet, Tue Jun 24 2014, 09:41PM
Hi,
i use optogate with IR PIN photohodiode (Its much fastert han photo transistor) look at my scheme i think its simple
Schmitt triger is there cause optogate its conected to logic 
Skynet, Tue Jun 24 2014, 09:41PM
Hi,
i use optogate with IR PIN photohodiode (Its much fastert han photo transistor) look at my scheme i think its simple
Schmitt triger is there cause optogate its conected to logic 
Re: Infrared trigger circuit
ZakWolf, Wed Jun 25 2014, 01:18PM
thanks, are those pnp and npn transistors ? there unlabeled
ZakWolf, Wed Jun 25 2014, 01:18PM
thanks, are those pnp and npn transistors ? there unlabeled
Re: Infrared trigger circuit
Skynet, Wed Jul 16 2014, 02:33PM
Yup
Skynet, Wed Jul 16 2014, 02:33PM
Yup
Re: Infrared trigger circuit
Conundrum, Sun Oct 05 2014, 07:32AM
I was looking at a variant of this to charge up airsoft pellets using UV and found that it wasn't feasible, however a beam break detector using a VCSEL is perfectly doable and costs less than £2 on ebay for the parts.
Conundrum, Sun Oct 05 2014, 07:32AM
I was looking at a variant of this to charge up airsoft pellets using UV and found that it wasn't feasible, however a beam break detector using a VCSEL is perfectly doable and costs less than £2 on ebay for the parts.
Re: Infrared trigger circuit
Signification, Mon Feb 23 2015, 02:20AM
ZakWolf, I see that you stated you have been in a lengthy search for a reliable triggering mechanism for coilgun stages. You didn't state the exact nature of the 'trouble', But here is a type I designed years ago to solve the problem due to EM 'coil interference'. It works by eliminating the need for ANY detectors, receivers, or wiring to be near the coils. Briefly, a hole is drilled where the projectile is to trigger the coil switch. The end of small length of optical fiber is placed in the hole and an electronic opto-detector is placed 'out of the way' on the other end of the fiber. The projectile is sharpened to a conical point (45 degree slope and shiny) on the rear end. Now, the optical source shines down the barrel (the safe end) With the projectile inserted, the light is blocked and can't travel down the barrel. As the end of the projectile passes the hole, the light striking the back of the projectile and reflecting from the 45 degree slant will squarely hit optical fiber, energizing the coil.
I had had good luck with this, but that was in the 1980's before LED's were super bright. So now I guess you could use a cool-looking color glow of your choice.
Signification, Mon Feb 23 2015, 02:20AM
ZakWolf, I see that you stated you have been in a lengthy search for a reliable triggering mechanism for coilgun stages. You didn't state the exact nature of the 'trouble', But here is a type I designed years ago to solve the problem due to EM 'coil interference'. It works by eliminating the need for ANY detectors, receivers, or wiring to be near the coils. Briefly, a hole is drilled where the projectile is to trigger the coil switch. The end of small length of optical fiber is placed in the hole and an electronic opto-detector is placed 'out of the way' on the other end of the fiber. The projectile is sharpened to a conical point (45 degree slope and shiny) on the rear end. Now, the optical source shines down the barrel (the safe end) With the projectile inserted, the light is blocked and can't travel down the barrel. As the end of the projectile passes the hole, the light striking the back of the projectile and reflecting from the 45 degree slant will squarely hit optical fiber, energizing the coil.
I had had good luck with this, but that was in the 1980's before LED's were super bright. So now I guess you could use a cool-looking color glow of your choice.
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