<p>A hydrofluidic oscillator including a momentum exchange fluidic amplifier coupled to a four-way reciprocal valve. The four-way valve is connected to control flow of hydraulic fluid from a source thereof to a using apparatus. The fluidic amplifier is connected to provide input signals to the four-way valve to cause the four-way valve to reciprocate responsive to the input signals. Both negative and positive feedback paths are provided from each outlet of the fluidic amplifier to the respective control ports to control oscillation of the four-way valve.</p>
