Control System for a Control Valve

An apparatus comprising:

• a control system for use with a control valve for use in well construction operations, wherein:
• the control valve applies:
• non-zero hydraulic pressure to a first port of a hydraulic cylinder when a control signal input voltage (CSi) is greater than a fraction value of a valve power supply voltage (VPSv);
• non-zero hydraulic pressure to a second port of the hydraulic cylinder when the CSi is less than the fraction value of the VPSv;
• and
• zero hydraulic pressure to the first and second ports when the CSi is substantially equal to the fraction value of the VPSv;
• the control system comprises:
• a voltage level shifter that produces a shift reference voltage (SHRv) substantially equal to the fraction value of the VPSv;
• a controller that produces a control system output voltage (CNTo) with a positive value, a negative value, or a substantially zero value in response to a control input voltage (CNTi) and the VPSv;
• and
• a voltage converter that receives the SHRv and CNTo and provides the CSi to the control valve;
• and
• the CSi is:
• greater than the fraction value of the VPSv when the CNTo is the positive value;
• less than the fraction value of the VPSv when the CNTo is the negative value;
• and
• substantially equal to the fraction value of the VPSv when the CNTo is the substantially zero value.