I have a problem and I wish to draw upon the collective genius of Arduino Forums…
I want to make a vacuum regulating device. Basically, I would program in some cycles (what vacuum, how long, repeat how many times) etc into an arduino that would then control a solenoid valve located in-line with the vacuum line. When I’m drawing a vacuum in the chamber, I’d apple a current to the normally-closed solenoid and allow the vacuum pump to suck the air out of the chamber. When I need to hold the vacuum, I’d simply stop applying current and let the solenoid valve close. When I need to release vacuum, I’d just use a vent valve on the chamber. Seems straight-forward enough… I realize that they need a lot of current, so I’d be using an external power source (most likely wall).
Right now, I’m thinking of using a MAP (manifold air pressure) sensor from an old vehicle for the vacuum sensor (so that I can detect when to switch the solenoid on or off). I need recommendations for vacuum solenoid valves that can take up to -28 inch of Hg. Also, are there any differences between solenoid valves and vacuum solenoid valves? Just because a solenoid is rated for 0~+X pressure shouldn’t mean that it can’t handle negative pressure…?
Cost is an issue and I’m hoping to keep the solenoid in the early~mid double digits if possible.
Thanks in advance!