Digital Hydraulic Controller

A digital hydraulic controller comprising:

• at least two rows of valve elements, one of the rows of valve elements being arranged to connect a supply line to a controller output and the other row of valve elements being arranged to connect the controller output to an outlet line;
• wherein each valve element of each row of valve elements has a flow cross section;
• wherein the valve elements of each row of valve elements are connected in parallel and are switchable individually or simultaneously in different combinations with each other;
• at least some of the valve elements of a row of valve elements have respectively a different flow cross section;
• wherein in each row of valve elements there is a smallest valve element which is smaller in flow cross section than the other valve elements in said row;
• and
• wherein the smallest valve element is duplicated so there are two smallest valves in each row of valve elements.

A system unit comprising:

• a differential cylinder having a piston to which a piston rod is attached on a rod side of the piston, the piston defining a piston side and the differential cylinder having a pressure chamber on the piston side, the rod defining the rod side and the differential cylinder having a pressure chamber on the rod side;
• a digital hydraulic controller comprising:
• two rows of valve elements, one of the rows of valve elements being arranged to connect a supply line to a first controller output and the other row of valve elements being arranged to connect the first controller output to an outlet line, wherein the first controller output is connected to the pressure chamber on the piston side;
• two further rows of valve elements, one of the further rows of valve elements being arranged to connect the supply line to a second controller output and the other further row of valve elements being arranged to connect the second controller output to the outlet line, wherein the second controller output is connected to the pressure chamber on the piston rod side;
• wherein each valve element of each row of valve elements has a flow cross section;
• wherein the valve elements of each row of valve elements are connected in parallel and are switchable individually or simultaneously in different combinations with each other, and wherein at least some of the valve elements of a row of valve elements have respectively a different flow cross section;
• wherein each row of valve elements has a smallest valve element which is smaller in flow cross section than the other valve elements in said row;
• and
• wherein the smallest valve element is duplicated so there are two smallest valves in each row of valve elements.