NOVELTY - The fluid-operated actuator assembly (10) has housing with a chamber on one side of the actuating element to which the outlet of the valve is connected to receive fluid from the fluid source when the valve is opened by the bi-stable electromagnetic device. The hydraulic actuator moves the actuating element to operate the hydraulic actuator. The bi-stable electromagnetic device is changed from an initial state to the final state when the hydraulic actuator is operated and changed from the final state to the initial state when the operation is terminated.    USE - Fluid-operated actuator assembly used in toilet cistern (claimed) operated by batteries, such as alternating current, hydro or solar power.    ADVANTAGE - The fluid-operated actuator assembly is powered by the pressurized water from a tap or flush water source. A bi-stable electromagnetic device, e.g. an electrical latching solenoid valve, is used to control the water flow from the water source. The actuator is triggered to operate the flushing valve such that the letting water in the cistern can be discharged immediately into the toilet bowl and the waste is flushed in the bowl so that the supply water pressure can be utilized as the major power source to complete the toilet flushing operation. The bi-stable electromagnetic device only requires an electrical signal of a limited duration to change state. Once latched, the latching solenoid is remained in the latched position without the need of electrical power such that the power consumption can be reduced and the use of battery power to control the actuator can be enabled. Since the flushing mechanism is driven by the supply water pressure, the power consumption of the control electronics and latching solenoid is extremely low.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a toilet cistern incorporating the fluid-operated actuator assembly; and    (2) a toilet incorporating fluid-operated actuator assembly.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the actuator assembly in operative condition.    Cistern (20)    Hydraulic cylinder (300)    Shuttle valve (500)    Hinge mechanism (600)    String (720)