I am designing an automatically played air instrument which consists of an air compressor, solenoid valves, a variety of pipes through which air flows and makes sounds, as well as an Arduino connected to a relay module for easily controlling the solenoid valves. When I apply electricity to solenoid valves, I hear (in addition to the usual clicking sound in solenoid) something like a popping sound (or maybe better described as a plop sound), probably caused by the sudden escape of compressed air. Is there a way to reduce this? I initially thought of driving the solenoid valves using PWM, so that it opens slower and the air makes less sound, but heard that this would not slow down the opening speed of the valve since solenoids cannot be slowed down… Any electrical or mechanical suggestions would be very helpful. The usual solenoid clicking sound is ok, I just need to reduce the air popping sound if possible…
(Below is the type of valve I am using; the pressure I use does not exceed 1-2 bars and I am using push-in connectors to hoses with 4mm inner diameter)
Best Answer
You are right in that PWM may not work since the solenoid was not specifically designed to be proportional. Still, it's worth a try to see what you get. You can also get proportional valves, although those will be more expensive.
One obvious answer is to add a muffler to the output of the valve. Perhaps even a old car muffler if you have the room, but it shouldn't be hard to make something yourself.