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Posted: Mon Jul 29, 2013 5:04 am
by jackssmirkingrevenge
Odd. Damn third world kids must have been improperly chained to their tables!

Have you tried it out disconnected from the QEV? Hook up the compressor to solenoid R, does air come out when the solenoid is off?

Posted: Mon Jul 29, 2013 5:06 am
by evilvet
Evilvet gives mouth to mouth on Port R
Air comes out of Port A

Posted: Mon Jul 29, 2013 5:09 am
by jackssmirkingrevenge
And solenoid on, lips to P, comes out of A but not R?

Posted: Mon Jul 29, 2013 5:41 am
by evilvet
Yup
And a nice tingle from the 12v supply if you are not careful.

Are we going to need to get a room for the next bit ?

Posted: Mon Jul 29, 2013 5:56 am
by jackssmirkingrevenge
evilvet wrote:Are we going to need to get a room for the next bit ?
HAHAHAHAHHA!!

:D :D :D

You made me LOL in front of my minions who are supposed to think I'm actually working :roll:

Blowing is all very well, but does it behave the same way when hooked up to the full 120 psi?

Posted: Mon Jul 29, 2013 2:54 pm
by evilvet
Exactly the same way at 120psi
The funny thing is, the solenoid has a manual trip switch, you can see the red button in the photo.

P-A under pressure from the compressor, the manual switch makes a nice click and works.
R-A which is what we want, manual does nothing, you have to use the volts on coil method but still no result.

Does that mean anything ?

EDIT: Just a thought. Given the valve is designed as NC, I suspect that the solenoid coil is only powerful enough to move the plunger the tiniest bit, relying on the main pressure to do the job. In better terms I mean internally piloted rather than direct acting.

Posted: Tue Jul 30, 2013 1:51 am
by jackssmirkingrevenge
Hmmm... curiouser and curiouser. I think your evaluation is correct, best explanation I can think of at least.

Posted: Tue Jul 30, 2013 5:37 am
by evilvet
PIA but there it is.

New firing plan
  • Press button on Arduino, digital pin 1 goes LOW
    LOW state on pin 1 enables HIGH state on pin 2
    Relay on pin 2 closes and solenoid trips
    P-A now enabled, chamber fills
    Ignore pin 1 thereafter, only needed to prime system
    Look for pulse on pin 3, that means FIRE button was pressed
    Write pin 2 LOW, relay unlatches, solenoid pilots through R and chamber dumps on QEV
    Write pin 2 HIGH again to relatch relay and trip solenoid filling chamber
    Rinse and repeat.
Not ideal but will work, the issue being that if I lose power for some reason the system will cycle.

SWMBO is away on a conference for the rest of the week so plenty of nag-free shed time to play with it.
I'll let you know how I go, thanks for the assist.