Abstract: A circuit or system having application for operating an implement or attachment for a power machine is disclosed. The circuit includes a first or primary valve, a second or auxiliary valve connected in series with the first valve and a supplemental line connected in parallel with the second valve to provide fluid to a supplemental system in parallel with the second valve.

Abstract: The present invention includes one illustrative embodiment that relates to a system that includes a piston pump, an open center valve, and an electronic controller. The piston pump is configured to provide a pressurized flow, such as to the open center valve. The open center valve is fluidly coupled to the piston pump, and configured thereby to receive the pressurized flow from the piston pump. The electronic controller is electrically connected to the piston pump. The electronic controller is also configured to receive operator input and to electronically control the piston pump, responsively to the input, to provide the pressurized flow to the first open center valve at a flow rate that is selectable from a range that is continuously variable from zero flow to a preselected maximum. Additional embodiments include, for example, a means for electronically controlling the piston pump, or a power machine with a frame, ground engaging members, and an engine.