Depth Control System For Raising And Lowering A Work Unit Of An Implement

An agricultural system comprising:

• an agricultural implement having a work unit;
• a hydraulic cylinder configured to raise and lower the work unit, the hydraulic cylinder having a base, a base port, a rod and a rod port, wherein the rod is configured to extend from the base when hydraulic fluid is supplied to the base port and withdrawn from the rod port, and wherein the rod is configured to retract toward the base when hydraulic fluid is supplied to the rod port and withdrawn from the base port;
• a pump configured to supply hydraulic fluid;
• a first electronically controlled proportional valve arranged between the pump and the base port of the hydraulic cylinder, wherein the first electronically controlled proportional valve is selectively controlled to proportionally meter hydraulic fluid from the pump to the base port;
• a second electronically controlled proportional valve arranged between the base port of the hydraulic cylinder and a reservoir, wherein the second electronically controlled proportional valve is selectively controlled to proportionally meter hydraulic fluid from the base port to a reservoir;
• and
• a pressure regulator arranged between the pump and the rod port of the hydraulic cylinder, wherein the pressure regulator is configured to regulate the hydraulic fluid to the rod port at a constant pressure.