electrohydraulic systems take advantage of the simplicity of hydraulic valve operation and the control possibilities available with electronics. Electronic valve controller is capable of unprecedented valve control accuracy and will monitor system conditions, maintain programmed values and also provides the needed interface. May be designed to maintain a constant upstream pressure to close limits, or to function as a pressure relief valve, or operate as an unloading valve in a by-pass system. These automated control systems are pilot operated to control fluid flow with an electrical signal and can be offered with solenoid control. Electro-hydraulic control, the automation equipment, constantly evaluates the signals from various sensors so that it can respond to driving style and operating conditions. This industrial instrument also disconnects the torque converter at idling to save fuel, and has the very wide ration spread.