Abstract: A DC solenoid coil current controller includes a rectifier, pulse width modulator, and power driver. The rectifier inputs an alternating current signal and a direct current signal, and outputs a rectified signal using at least one of the alternating current signal and the direct current signal. The pulse width modulator outputs a pulse width modulated signal in response to the rectified signal. The power driver controls a DC solenoid coil using the pulse width modulated signal, thereby enabling a direct current DC solenoid coil to be controlled in response to the alternating current signal. A method of controlling current to a DC solenoid coil is also disclosed.

Abstract: A DC solenoid coil current controller includes a rectifier, pulse width modulator, and power driver. The rectifier inputs an alternating current signal and a direct current signal, and outputs a rectified signal using at least one of the alternating current signal and the direct current signal. The pulse width modulator outputs a pulse width modulated signal in response to the rectified signal. The power driver controls a DC solenoid coil using the pulse width modulated signal, thereby enabling a direct current DC solenoid coil to be controlled in response to the alternating current signal. A method of controlling current to a DC solenoid coil is also disclosed.

Abstract: According to aspects described herein, there is disclosed a method of and system for indicating a fault associated with a fluid valve moveable between an open and a closed operative position. The method and system compare a valve state indicator to a valve last command, wherein the valve state indicator represents a detected operative position of the valve and the valve last command being an operative command sent to the fluid valve. The method and system also initiate a fault indication after a predetermined time delay relative to the valve last command being sent and when the valve state indicator does not match the valve last command. After the time delay a fault indication can be initiated immediately upon receipt of a different valve state indicator.

Abstract: According to aspects described herein, there is disclosed a method of and system for indicating a fault associated with a fluid valve moveable between an open and a closed operative position. The method and system compare a valve state indicator to a valve last command, wherein the valve state indicator represents a detected operative position of the valve and the valve last command being an operative command sent to the fluid valve. The method and system also initiate a fault indication after a predetermined time delay relative to the valve last command being sent and when the valve state indicator does not match the valve last command. After the time delay a fault indication can be initiated immediately upon receipt of a different valve state indicator.

Abstract: A method to create a drilling performance assessment ratio. The ratio includes the steps of establishing a technical minimum time limit standard for each of multiple sequential steps required for a drilling operation. Actual time performance for each of the multiple steps is measured for an actual drilling operation. The actual performances are compared to the technical time limit standards in order to produce a drilling performance ratio.