What is the Proper Control Current for Proportional Valves?

Proportional valve spool position is directly related to the applied current, not the applied voltage. This is because coil resistance is not constant, but rather it increases with temperature. Therefore, one should limit the maximum current to the rating of the coil as specified by the valve manufacturer. The current ranges from 1.0 amps to 2.0 amps according to most valve manufacturers. The higher current range may be experienced for larger flow rated valves and those subject to high ambient temperature/continuous duty applications. In high temperature conditions you can run out of voltage and will not be able to use the full resolution of the product. So remember to size the valve with these current limits in mind.

Proportional valve technology specialists recommend control via PWM (Pulse Width Modulation). PWM provides control technology that induces less heat to the operating coil and thereby enhances the performance of the proportional valve.

Proportional valves operate at 12 VDC or 24 VDC depending upon the valve manufacturer. The industrial market typically uses 24 VDC while the mobile market uses both 12 VDC and 24 VDC to power the coils of proportional valves in the circuits depending upon the equipment power source.