Solenoid valve control system

A solenoid valve that comprises:

• a valve body in which a valve spool is slidably mounted, and
• a solenoid assembly mounted at one end of said valve body, said solenoid assembly comprising:
• a solenoid having a plunger operatively coupled to said spool and a solenoid coil for actuating said plunger, and
• a solenoid valve driver circuit including a circuitboard assembly carried as part of said solenoid assembly, said circuitboard assembly having a power supply responsive to external power for supplying power to said driver circuit and said solenoid, and a microprocessor-based control circuit responsive to external control signals for controlling actuation of said solenoid coil,
• said control circuit including an electronic switch having primary current conducting electrodes connected in series with said solenoid coil across a power source and a control electrode for receiving valve control signals from said control circuit, and
• means for monitoring conductive condition of said coil, said means being connected across said electronic switch between said primary current conducting electrodes, in parallel with said electronic switch and in series with said coil across said power source, for detecting current through said coil from said power source when said electronic switch is non-conductive.