Flow control solenoid valves might do the 5 Hz. open and close in your car at 5 clicks per second. As in simulator.
However, if the solenoid valve is 30 Hz. do you think the valve is all the way open or all the way closed 30 times a second?
Valves of this sort have a variable flow but they do not open and close fully at higher frequencies.
Say at 50 Hz. our solenod valve hoover's about mid-position (the construction of solenoid determines the frequency for mid-position) and then the amount of duty cycle determines how much the valve is open.
This solenoid method can be used if duty cycle is around range of 20-80%.
