| abstract |
A control system for applying power to a solenoid operated valve in a well completion within a borehole. The control system includes a programmable power supply for selectively applying electric power to a solenoid coil of the valve. The control system operates to apply a higher value of current to the solenoid to open the valve and a second lower value of current to maintain the operation of the solenoid in an open state and also to interrupt all current to the solenoid to close the valve. A timer controls the length of time the higher current value can be applied to the solenoid if the valve does not open and the length of delay time which must be included before again attempting to open the valve. The control system continuously monitors the state of actuation of the valve by means of an inductance monitor for determining the position of the armature of the solenoid and, thus, the state of the valve. |