Opening time of sprinkler valve

[crazyfreak0075]

I know nothing technical abut sprinkler valves except the basics. I plan on making an automatic bbmg with a 555 timer circut and was going to use some type of solenoid valve to reglulate the air going into the chamber, any who, i was wondering if these sprinkler valves were slow opening, could they stand up to being opened and closed in .2 sec without any lag time. Would modifying them make it faster.

[noname]

I'm not quite sure how fast they open and close, but a modified valve will open about 3 times faster and close as soon as you close the pilot valve, while a solenoid valve will stay open until no more pressure is in the chamber.

[jrrdw]

They may open that fast, but it takes longer to close back up. Besides, Sprinkler Valves are dump valves anyway, (they let it out all at once). Aren't you looking for more of a steady airflow instead of all at once?

[crazyfreak0075]

yes jrrdw i think i do, this is basically what i need a valve to do. i pull the trigger the timer starts it opens the valve releasing small amounts of air ever .2 seconds as long as the trigger is still depressed. Any segestions on what type of valve i would need if it isn't sprinkler.

[jrrdw]

I forget where here in spudfiles it is, but i seen a brass solinoid valve, the only problem i can think of so far is in order to regulate airflow without looseing power??? This is kind of a tall order you put in, but i'm sure it can be done. It also depends on what kind of timer your planing on useing. The kind i'm imageing are the kind that turn house lights on and off. ???

[crazyfreak0075]

The timer i will be useing is a 555 timer its a small IC chip and you can manipulate the time it takes by changing the different values of the capacitors and resistors. but thats not the part im worried about. what do u mean by

the only problem i can think of so far is in order to regulate airflow without looseing power?

i dont understand how i will loose power.

[Hotwired]

5 times a second is serious stuff.

Don't auto bb guns running on gas use a rotating mechanism to knock back a poppet valve to deliver gas bursts?

[crazyfreak0075]

yeah but im just trying something not too complicated. also if the 5 bb's per sec is too mutch i can always change the timer value to make it go slower. i just need a valve that can open and close with an electronic signal, kinda like a switch.

[jrrdw]

The lower/slower the air input, the less power. It's 1+1=2 man, think about it.

[crazyfreak0075]

yeah im sorry dude i just read ur question wrong good point. so a solenoid vale will work in my case. any ideas on the regulating pressure/power problem.

[jrrdw]

If you can find a valve that will open and close very fast, i think the idea is to use a higher pressure, that way you keep the power. The problem now becomes how to close it back up under high pressure. If you can build it in line so that the stored pressure helps close the valve ???

As for the power supply, thats better left to someone else, not really my area.

[crazyfreak0075]

I'm sorry as stated before i don't know much about soleniod valves so please bear with me but the part im not understanding is the closeing of the valve i would have some sort of chamber holding the air it released so i have somewhat equal air pressures on both sides making it easier for it to close then just having one side with air rushing through at 100 psi. Am i correct.

[Hotwired]

You want direct acting solenoid valves.

This webpage has some very handy diagrams of why and at the bottom it says DA solenoids have a fully open -> fully closed speed of 50-60ms: http://www.plastomatic.com/pomsolenoid.html

Since you're planning on it being opened and closed every 200ms it ought to work.

[crazyfreak0075]

Hey thanks hotwired.