Proportional Solenoid Valve Operation
Proportionally controlled solenoids are used in fluid-power valve applications to proportionally control flow (or pressure) from zero to maximum flow as a function of duty cycle. At zero duty cycle, the solenoid is stationary, the valve is closed, and flow is zero. At 50% duty cycle, the solenoid moves through full stroke and opens the valve. The valve is only allowing full flow 50% of the time, so the time-averaged flow, in theory, is 50% of maximum flow. This type of control is called digital because the valve is fully open or fully closed - On or Off.